^a^^aa^ 

EX  L1BRIS 


STATE  OF  COLORADO 

COOPERATIVE  OIL  SHALE  INVESTIGATION 

2S2?  (In  Cooperation  With  the  United  States  Bureau  of  Mines) 


MARTIN  J.  GAVIN,  Engineer  in  Charge 


"^ERSITYOFCAI 


BULLETIN  NO.  1 

Ider,  July  1,1921 


Short  Papers  from  the  Co- 
operative Oil-Shale 
Laboratory 


By 


MARTIN  J.  GAVIN  and  LESLIE  H.  SHARP 


Denver,  Colorado 

EAMES  BROTHERS,  STATE  PRINTERS 
1921 


STATE  OF  COLORADO 
COOPERATIVE  OIL  SHALE  INVESTIGATION 

(In  Cooperation  With  the  United  States  Bureau  of  Mines) 
MARTIN  J.  GAVIN,  Engineer  in  Charge 


BULLETIN  NO.  I 

Boulder,  July  1,1921 


Short  Papers  from  the  Co 

operative  Oil-Shale 

Laboratory 

By 
•MARTIN  J.  GAVIN  «nd  LESLIE  H.  SHARP 


Denver,  Colorado 

EAMES  BROTHERS,   STATE  PRINTERS 
1921 


Plate 
Plate  II. 
Plate  III. 


LIST  OF  ILLUSTRATIONS 

Page 
I.      The  Co-operative  oil-shale  laboratory  at  Boulder 5 


Typical  oil-shale  ledge  in  Colorado 

Typical  oil-shale  formation  in  Colorado 8 

Plate  IV.  Horizontal  retort  at  Boulder  laboratory 12 

Plate  V.  Map  of  Northwestern  Colorado 26 


FIGURES 

Page 

Fig.  1.      Graphic  representation  of  retorting  test  No.  1 30 

2.  Graphic  representation  of  petortirigttest  No.  2 31 

3.  Graphic  representation  of  retorting  test  No.  3 32 

4.  Graphic  representation •  cl  telortijfi-g'  te£t  No.  4 33 

5.  Graphic  representation  of  retorting  test  No.  5 34 

6.  Graphic  representation  of  retorting  test  No.  6 35 

1.      Graphic  representation  of  retorting  test  No.  1 , 36 

8.  Graphic  representation  of  retorting  test  No.  8 37 

9.  Graphic  representation  of  retorting  test  No.  9...  ...38* 


CONTENTS 


Page 
Letter  of  transmittal 6 

Preface    A 7 

Introduction    9 

Acknowledgments  . 11 

Fuel  values  of  oil-shale  and  oil-shale  products 13 

Summary  .20 

Observations  on  shale  gas . 22 

Conclusions '. 24 

Results  of  nine  oil-shale  retorting  tests - 27 

Introduction 27 

Experimental   plan 27 

Description  of  experimental  work .28 

Discussion  of  retorting  tests 39 

Conclusions   40 

Future  retorting  work 41 

Analytical  distillation  of  shale  oil  from  Colorado  oil-shale 42 

Introduction 42 

Laboratory  procedure  for  examining  shale  oils 43 

Interpretation  of  results  of  distillation  analyses ..45 

Comparison  of  analyses  of  shale  oils 51 

Thermal  calculations  on  the  retorting  of  oil-shales 52 

Introduction 52 

Method  of  making  calculation  of  heat  required  for  retorting 52 

Comparison  of  calculated   and  experimentally  determined   heat 
requirements 55 

Calculation  of  heat  available  from  shale  gas  and  spent  shale 56 

Thermal  efficiencies  of  retorts  necessary  to  retort  oil-shales  of 
different  richness   56 

Convenient  factors  for  use  in  oil-shale  calculations....  ...61 


KfcLOSOQ 


TABLES 

Page 

Table              I.     Summary — heats  of  combustion  or  fuel  values  of  oil- 
shale  and  its  products 14 

II.      Factors  necessary  in  calculating  heat  balances 17 

III.  Heat   distribution   in   one   gram    of   fresh   shale   and 

products  obtained  from  it 17 

IV.  Percentage  heat  distribution ...18 

V.      Heating  values  of  shale  and  shale  products  compared 

with  other  fuels....  18 

VI.      Table  showing  relation  between  jgas  production,  oil 
production,    temperature    and    heating    value    of 

gas  produced  23 

VII.      Composition  of  shale  and  other  gases 25 

VIII.      Summary   of   nine   retorting   tests   on    Colorado    oil- 
shales 29 

IX.      (A-D)    Analytical    distillation   of   shale    oil    from 

Colorado  oil-shale  48-49 

•    IX.      (E)    Analytical   distillation   of   shale   oil   from    Scot- 
land     50 

IX.      (F)   Analytical  distillation  of  crude  oil  from  Penn- 
sylvania   50 

X.      Composition  by  weight  of  one  ton  of  shale 57 

XI.      Total  heating  value  of  ^oil-shales  of  varying  richness. .57 
XII.      Heat  value  of  products  of  oil-shales  of  different  rich- 
ness     57 

XIII.  Heat  recoverable  in  products  of  oil-shales  of  varying 

richness   58 

XIV.  Heat  required   to   retort   oil-shales   of   varying   rich- 

ness  59 

XV.      Necessary  thermal  efficiencies  of  retorts 60 

XVI.      Frequently  used   equivalents 61 

XVII.      Some  constants  for  shale  and  shale  products 62 

XVIII.      Heat  equivalents 62 

XIX.      Temperatures  62 

XX.      Weight  of  shale 63 

XXI.      Petroleum  oil  table  for  converting  specific  gravity  to 

Baum6  degrees 63 

XXII.      Petroleum  oil  table  for  converting  Baum6  degrees  to 

specific  gravity  64 

XXIII.  Temperature     corrections     to     readings     of     specific 

gravity  hydrometers  in  American  petroleum  oils 
at  various  temperatures 65 

XXIV.  Temperature     corrections     to     readings     of     Baum6 

hydrometers  in  American  petroleum  oils  at  vari- 
ous temperatures   ., 66 

XXV.      Relation  between  altitude  and  barometric  pressure.. 6  7 
XXVI.      Factors    for    use   in    calculating   results    of    oil-shale 

assays    67 

XXVII.      Other   factors   frequently   used    in    making   oil-shale 

assay  calculations  ...68 


LETTER  OF  TRANSM1TTAL 

DEPARTMENT  OF  THE  INTERIOR 

BUREAU  OF  MINES 

WASHINGTON 

TO  HIS  EXCELLENCY, 

The  Honorable  Oliver  H.  Shoup, 
Governor  of  Colorado. 

Sir: 

I  have  the  honor  to  transmit  six  short  papers  by  M.  J.  Gavin, 
Oil  Shale  Technologist,  U.  S.  Bureau  of  Mines,  and  L.  H.  Sharp, 
Chemical  Engineer  for  the  State  of  Colorado.  These  papers  pre- 
sent the  results  of  certain  studies  made  at  the  Co-operative  Oil 
Shale  Laboratory,  Boulder,  Colorado.  Further  reports  of  the 
studies,  which  are  still  in  progress,  will  be  transmitted  when  com- 
pleted. 

Cordially  yours, 

H.  FOSTER  BAIN, 

Director, 
U.  S.  Bureau  of  Mines. 


PREFACE. 

This  paper  is  a  presentation  of  the  results  of  preliminary 
studies  at  the-Colorado  Co-operative  Oil  Shale  Laboratory,  Boulder, 
Colorado,  which  were  begun  February  1,  1920,  by  the  U.  S.  Bureau 
of  Mines  and  the  State  of  Colorado,  under  a  co-operative  agreement 
entered  into  by  the  Bureau  and  the  State,  utilizing  funds  which 
were  provided  by  the  State,  and  the  services  of  engineers  provided 
by  the  Bureau. 

The  investigations  are  for  the  purpose  of  determining  by  large- 
scale  laboratory  retorting  tests,  those  conditions  which  will  pro- 
duce optimum  yield  of  best  quality  of  products  from  Colorado 
shales. 

It  seems  fairly  certain  that  the  peak  of  the  petroleum  produc- 
tion curve  in  the  United  States  will  be  reached  in  a  few  years,  but 
the  curve  of  consumption  will  contine  in  its  upward  rise.  To  meet 
this  situation,  either  imports  must  be  increased  in  the  future,  or 
means  must  be  found  to  utilize  the  immense  oil-shale  deposits  of 
Colorado  and  other  western  states  as  a  source  of  the  needed  oil. 

This  last  is  not  a  simple  problem.  While  oil  shales  have  been 
worked  in  Scotland  and  France  for  many  years,  it  was  in  competi- 
tion with  high-priced  petroleum  products  and  with  low  labor  costs, 
with  the  added  advantage  that  the  industry  is  there  situated  in  a 
densely  populated  region  where  a  ready  market  for  oil  and  ammo- 
nimum' products  was  available.  Even  these  long-established  indus- 
tries are  passing  through  a  difficult  period  at  present.  The  oil 
shales  of  the  Rocky  Mountain  region  occur  in  sparsely  settled  com- 
munities and  their  development  will  mean  bringing  into  the  region 
great  numbers  of  working  men,  with  their  families,  for  whom  hous- 
ing and  the  conveniences  of  living  must  be  provided,  in  addition  to 
the  millions  of  dollars  which  must  be  spent  in  constructing  plants, 
equipping  mines,  and  providing  transportation  facilities.  About 
one  million  barrels  of  oil  are  now  produced  each  day  in  the  United 
States  and  to  produce  one  barrel  of  oil  from  oil-shale  will  involve 
the  mining  and  crushing  of  at  least  one  ton  of  tough  material,  heat- 
ing it  to  a  high  temperature  and  finally  disposing  of  three-fourths 
of  a  ton  of  waste  residue. 

It  naturally  follows  that  an  enterprise  which  bids  fair  to  be 
so  important  to  the  State  of  Colorado  justifies  the  most  careful 
investigation  to  assure  that  development  shall  be  along  the  right 
lines,  since  the  loss  of  capital  resulting  from  too-hasty  construction 
of  unsuitable  plants  would  be  certain  to  prove  an  obstacle  to  secur- 
ing the  needed  capital  for  the  development  of  the  industry.  Until 
the  fundamental  factors  underlying  the  development  of  the  oil 
shales  of  the  Rocky  Mountain  region  have  been  clearly  and  accu- 
rately ascertained,  no  sound  development  of  the  oil  shale  industry 
will  be  possible. 

A.  W.  AMBROSE, 
Chief  Petroleum  Technologist, 

Washington,  D.  C.,  U.  S.  Bureau  of  Mines. 

May  15,  1921. 


8    l  SHORT  PAPERS  FROM  THE 


Plate  II.     Typical  Oil-Shale  Ledge   in  Colorado 


Plate   III.     Typical  Oil-Shale  Formation  in  Colorado 


CO-OPERATIVE  OIL-SHALE  LABORATORY 

INTRODUCTION. 

In  January,  1920,  the  State  of  Colorado  and  the  United  States 
Bureau  of  Mines  entered  into  a  co-operative  agreement  for  the  con- 
duct of  laboratory  investigations  on  the  oil-shales  of  Colorado. 
Under  this  agreement  a  laboratory  has  been  installed  and  equipped 
at  the  State  University,  Boulder,  Colorado,  and  a  research  staff 
organized.  It  is  the  primary  purpose  of  the  investigation!  work  to 
determine  the  most  favorable  conditions  of  retorting  Colorado  oil- 
shales  to  yield  the  most  of  the  best  products  from  them. 

Work  of  this  nature  involves  retorting  the  oil-shale  under  many 
conditions  and  the  examination  of  products  obtained  in  each  test  to 
determine  the  effect  of  the  conditions  imposed  during  the  test. 
New  problems  continually  arise  which  call  for  the  development  of 
new  methods  for  their  solution  and  frequently  interesting  develop- 
ments are  investigated  only  to  give  results  of  negative  value.  It 
becomes  apparent  that  a  great  deal  of  time  will  be  required  before 
the  main  purpose  of  the  investigation  can  be  accomplished.  How- 
ever, in  the  course  of  the  main  investigation  it  was  necessary  to 
take  up  certain  side  investigations  which  were  directly  connected 
with  the  main  plan  of  the  work.  Many  of  these  minor  investigations 
have  yielded  results  of  sufficient  interest  and  importance  that  it 
has  been  considered  worth  while  to  bring  them  to  the  attention  of 
the  public  before  the  principal  results  of  the  main  investigation  can 
be  published. 

Two  papers1  dealing  with  the  program  of  the  investigations 
and  with  some  of  the  work  already  accomplished  have  already  been 
published  in  mimeographed  form  by  the  Bureau  of  Mines,  and  it  is 
the  purpose  of  the  Bureau  and  State  to  continue  publishing  short 
reports  as  frequently  as  material  becomes  available.  The  final 
results  of  the  completed  investigations  are  to  be  the  subject  of  a 
Bureau  of  Mines  bulletin. 

This  present  paper  deals  with  several  subjects  which  will  be  of 
interest  to  those  engaged  in  the  development  of  an  industry  from 
the  immense  deposits  of  oil-shales  in  Colorado  and  adjacent  states. 
It  is  a  compilation  of  six  short  reports  which  have  been  prepared  in 
the  course  of  the  investigational  work.  The  fuel  values  of  oil-shale 
and  oil-shale  products  are  discussed  in  the  first  paper;  the  nature 
and  composition  of  shale  ga,s  is  presented  in  the  second ;  the  third 
gives  production  tables  and  curves  for  shale  oil  as  obtained  from 
the  horizontal  rotary  retort  used  in  the  Boulder  laboratory;  the 
analytical  distillation  of  shale  oils  is  taken  up  in  the  fourth  report  ; 
the  fifth  gives  data  on  thermal  calculations  for  the  retorting  of  oil- 
shales,  and  the  sixth  is  a  tabulation  of  factors  and  formulae  which 
have  been  found  of  value  in  the  Boulder  co-operative  laboratory  and 
the  oil-shale  laboratory  at  the  Intermountain  Experiment  Station 
of  the  Bureau  of  Mines,  Salt  Lake  City,  Utah. 

1  Gavin,  M.  J.,  and  Sharp,  L.  H.,  Investigation  of  the  fundamentals  of 
oil-shale  retorting-,  Bureau  of  Mines.  Reports  of  Investigations,  Serial  No 
2141,  July,  1920,  4  pp.  Reprinted  in  Eng.  World,  Sept.,  1920. 

Gavin,  M.  J.,  and  Sharp,  L.  H.,  Some  physical  and  chemical  data  on 
Colorado  oil-shale,  Bureau  of  Mines,  Reports  of  Investigations,  Serial  No. 
2152,  August,  1920,  8  pp.  Reprinted  in  Eng.  and  Min.  Jour.,  Sept.  18  1920- 
Oil  Paint  and  Drug  Reporter.  Sept.  13,  1920;  and  Gas  Age,  Sept.  25,  1920 


10  SHORT  PAPERS  FROM  THE 

Attention  is  called  to  the  fact  that  the  data  given,  except  those 
in  the  last  paper,  can  be  expected  to  apply  only  to  the  oil-shale 
worked  with  and.  the  products  recovered  therefrom  under  the  par- 
ticular conditions  used  in  the  investigations.  However,  the  material 
being  worked  with  is  believed  to  be  a  fairly  representative  sample 
of  Colorado  oil-shale,  and  if  due  allowances  are  made  for  the  vary- 
ing richness  of  different  shales,  the  results  may  be  expected  to  be 
applicable,  with  a  reasonable  degree  of  accuracy,  to  all  shales  of 
the  Green  River  formation. 


CO-OPERATIVE  OIL-SHALE  LABORATORY  11 


ACKNOWLEDGEMENTS. 

The  writers  gratefully  acknowledge  the  services  rendered  by 
Mr.  James  Duce,  State  Oil  Inspector  of  Colorado,  in  perfecting 
co-operative  agreements  and  in  arranging  for  laboratory  and  office 
space,  and  are  especially  grateful  to  him  for  the  many  valuable 
suggestions  he  has  made  and  for  the  deep  interest  he  has  taken  in 
the  work. 

To  Professors  John  A.  Hunter  and  Jay  W.  Woodrow  as  well  as 
other  faculty  members  and  the  regents  of  the  University  of  Colo- 
rado, thanks  are  due  for  the  co-operative  spirit  shown  by  them  and 
for  the  material  assistance  they  have  rendered  in  many  ways.  Ac- 
knowledgements are  made  to  Alvah  M.  Hovlid,  of  the  Co-operative 
Laboratory,  Boulder,  for  assistance  in  carrying  out  much  of  the 
experimental  work  leading  to  the  results  herein  presented,  and  to 
L.  C.  Karrick  and  J.  J.  Jakowsky,  the  authors'  associates  in  the 
Bureau  of  Mines  Experiment  Station,  Salt  Lake  City,  Utah,  for 
assistance  in  preparing  manuscript  and  for  valuable  suggestions  as 
to  the  conduct  of  the  experimental  work.  Mr.  Jakowsky  also  pre- 
pared curves  Nos.  1  to  9.  Manuscript  was  prepared  by  Miss  Louise 
Helson  of  the  Salt  Lake  City  Station  of  'the  Bureau  of  Mines,  and 
Mr.  A.  T.  Strunk  of  the  Boulder  Laboratory.  Mr.  Arthur  J. 
Franks  of  Golden,  Colorado,  kindly  supplied  certain  results  of  his 
oil-shale  studies  for  use  in  connection  with  the  paper  on  Thermal 
Calculations  on  the  Retorting  of  Oil  Shales.  The  manuscript  was 
constructively  critised  by  T.  E.  Swigart  and  N.  A.  C.  Smith  of 
the  Bureau  of  Mines. 


12 


SHORT  PAPERS  PROM  THE 


Plate  IV.     Horizontal  Retort  at  Boulder  Laboratory.     Scrubbers  in  Foreground 


CO-OPERATIVE  OIL-SHALE  LABORATORY 


13 


FUEL  VALUES  OF  OIL-SHALES  AND 
OIL-SHALE  PRODUCTS. 

Subsequent  to  the  publication1  of  the  heats  of  combustion  of  a 
fresh  oil-shale  yielding  42.7  gallons  of  oil  to  the  ton,  and  the  spent 
shale  and  oil  derived  therefrom,  it  has  seemed  advisable  to  secure 
similar  data  for  shales  of  varying  oil  yield  and  different  physical 
and  chemical  characteristics,  in  order  to  furnish  geologists  and 
engineers  with  an  accurate  basis  for  calculating  the  thermal  values 
of  oil-shales  and  their  products,  especially  for  possible  retort  fuels. 

Accordingly,  six  samples  of  shale  of  diversified  character  as 
indicated  below  were  selected,  determinations  of  the  heats  of  com- 
bustion of  the  fresh  shales  and  of  the  spent  shales  and  oils  derived 
from  them  were  made,  and  the  heat  value  of  the  derived  gases  cal- 
culated. 


CHARACTERISTICS  OF  SHALES  USED. 


Oil  Yield 

Water  Yield 

on  Assay; 

on  Assay 

Physical 

Chemical 

Gals. 

From 

Nature 

Gals. 

No. 

Composition 

Nature 

Per  Ton 

Locality 

Oil 

Per  Ton 

1 

Massive 

Limy 

10.0 

Dry  Fork  1 

Light 

1.06 

2 

Massive 

Siliceous 

28.0 

Conn    Creek  l 

Med.  waxy 

4.22 

3 

Massive 

Siliceous 

37.0 

Conn    Creek1 

Med.  waxy 

3.16 

4 

Massive 

Siliceous 

42.7 

Conn    Creek  1 

Med.  waxy 

3.16 

5 

Thin   "paper" 

Mouldy 

organic 

75.5 

Dry  Fork  x 

Gassy  light 

6.04 

6 

Semi-massive 

Siliceous 

"paper" 

organic 

76.2 

Mt.  Logan  1 

Med.  waxy 

6.30 

1  Near  DeBeque,  Colo. 

In  all  cases  the  samples  were  crushed  to  — i/4  mesh  in  a  chip- 
munk crusher,  the  crushed  shale  thoroughly  mixed  and  sampled, 
then  approximately  one  pint  of  each  shale  was  taken  for  assay. 

The  assays  were  made  by  the  method  recommended  by  the 
U.  S.  Bureau  of  Mines  for  oil-shale  assay.2  The  residues  were  care- 
fully weighed  and  sampled  and  distillation  losses  noted.  Oils  were 
preserved  in  glass  stoppered  flasks.  All  samples  of  fresh  and  spent 
shale  were  ground  to  pass  a  100  mesh  screen  and  heats  of  combus- 
tion determined  in  the  standard  Emerson  bomb  calorimeter.  The 
heat  of  combustion  of  oils  was  then  determined  in  the  same  appara- 
tus. (300  to  350  pounds  of  oxygen  pressure  were  used  in  all  deter- 
minations and  temperature  readings  were  taken  with  a  Beckman 
differential  thermometer. )  Check  determinations  were  run. 

The  determinations  were  corrected  for  unburned  material3  as 
shown  in  the  following  table.  A  further  check  in  the  form  of  total 
ignition  loss  determination  was  made. 

1  Gavin,  M.  J.,  and  Sharp,  L.  H.,  Some  physical  and  chemical  data  on 
Colorado  oil-shale,  Bureau  of  Mines,  Reports  of  Investigations,  Serial  No. 
2152.  August,  1920.  8  pp. 

2  Karrick,   L.  C.,  A  convenient  and  reliable  retort  for  assaying  oil-shales 
for   oil   yield,    Bureau   of   Mines,    Reports    of   Investigations,    Serial   No.    2229, 
March,   1921.     Reprinted  in  Eng.  and  Min.   Jour.,  April   30,    1921. 

3  Gavin,    M.   J.,   and   Sharp,    L.   H.,    Some   physical   and   chemical   data  on 
Colorado    oil-shale,    Bureau    of   Mines,    Reports   of   Investigations     Serial    No. 
2152,   August,   1920.  8  pp. 


14 


SHORT  PAPERS  FROM  THE 


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CO-OPERATIVE  OIL-SHALE  LABORATORY  15 

A  careful  examination  of  this  table  for  various  ratios  and  rela- 
tionships yields  the  results  noted  below. 

A.  It  is  often  said  that  the  lighter  the  shale  the  higher  its 
oil  yield.  Accordingly  the  oil  yield  was  divided  by  the  reciprocal 
of  the  specific  gravity  but  the  result  was  far  from  constant.  Vari- 
ous other  attempts  to  find  a  mathematical  relationship  failed.  So 
far  as  these  experiments  indicate,  there  is  none. 

B. '  The  distillation  loss  of  oil  shale  is  composed  of :  (a)  the 
oil  volatilized,  (b)  the  water  volatilized,  (c)  the  gas  formed,  and 
(d)  variable  positive  and  negative  losses  due  to  decomposition  of 
some  of  the  chemical  constituents  of  the  mineral  matter  and  oxida- 
tion of  others. 

The  percentage  of  loss  due  to  each  of  the  above  is  as  follows: 

(a)  Number  of  gallons  of  oil  per  ton  of  shale  X  0.375. 
(specific  gravity  =  0.900).     (Factor  obtained  by  dividing 
weight  of  a  gallon  of  shale  oil  by  2000  (pounds  in  a  ton) 
X  100.) 

(b)  Gallons  of  water  per  ton  of  shale  X  0.416.    (Fac- 
tor obtained  by  dividing  weight  of  a  gallon  of  water  by 
2000  X  100.) 

(c)  Cubic  feet  of  gas  per  ton  of  shale  X  0.00025. 
(density  =  0.656;  air  =  1.000).     (Factor  obtained  by  di- 
viding weight  of  a  cubic  foot  of  gas  by  2000  X  100.) 

(d)  Sum  of  (a  +  b  +  c)  subtracted  from  total  per 
cent  loss  on  distillation  as  shown  by  assay  or  plant  records. 

C.  In  a  very  general  way  it  may  be  said  that  the  greater  the 
ignition  loss  the  greater  the  oil  yield.    This  relation,  however,  must 
not  be  accepted  as  a  satisfactory  basis  for  estimating  oil  yields  from 
oil-shales,  because  ignition  losses  include  losses  that  do  not  go  to 
make  up  oil,  on  distillation,  such  as  losses  due  to  decomposition  of 
the  carbonates  in  the  shale,  water  of  crystallization,  and  the  like. 

D.  When  the  oil  yield  is  compared  with  the  heat  of  combus- 
tion a  somewhat  more  definite  ratio  is  found.     Dividing  heat  of 
combustion  of  the  shale  in  B.  T.  U.  per  pound  by  assay  yield  of  oil 
in  gallons  per  ton,  gives  a  series  of  numbers  averaging  103.9,  and 
omitting  the   " paper"   shale1,   averaging   106.6,   with   a  variation 
between  samples  of  less  than  ±  5.0  per  cent.     This  number  is  the 
factor  F  in  Table  I. 

Conversely,  if  the  assay  yield  of  oil  in  gallons  per  ton  of  any 
shale  is  known,  its  heat  value  in  B.  T.  U.  per  pound  can  be  closely 
approximated  by  multiplying  oil  yield  by  this  factor  (106.6).  If 
it  is  desired  to  express  the  heat  value  of  the  shale  in  calories  per 
gram,  the  above  factor  becomes  59.24. 

Example:  An  oil-shale  is  assayed  and  found  to  yield  50  gal- 
lons of  oil  per  ton. 

50  X  106.6  =  5330  B.  T.  U.  per  pound  /    Heat   of  combustion   of 
or  50  X  59.24  =  2960  calories  per  gram    ?       shale. 

1  All  the  results  obtained  seem  to  indicate  a  different  set  of  constants  for 
"paper"  shales. 


16  SHORT  PAPERS  FROM  THE 

Later  calculations  (not  experimental  evidence)  seem  to  indi- 
cate that  the  fuel  value  factor  may  decrease  slightly  for  the  shales 
yielding  much  over  60  gallons  of  oil  per  ton.  The  factor  given, 
however,  is  sufficiently  close  to  serve  as  a  good  approximation  for 
most  shales,  especially  as  shales  yielding  over  50  gallons  of  oil  per 
ton  are  rather  exceptional. 

The  available  heating  value  of  an  oil-shale  will,  of  course,  be 
influenced  by  the  water  content  of  the  shale,  since  the  water  must 
be  vaporized  during  combustion,  when  it  is  present,  and  thus  sub- 
tracts from  the  total  heating  value  as  calculated  by  the  above 
method. 

It  may  be  that  the  composition  of  kerogen  in  the  shales  of  vari- 
ous widely  separated  localities  or  geological  horizons  may  be  suffici- 
ently diverse  to  necessitate  separate  determinations  of  the  above 
factor.  The  problem  merits  further  investigation.  The  variation 
of  the  "paper"  shale  considered  in  connection  with  the  character 
of  oil  yielded  by  it,  argues  for  a  different  factor  in  this  case  at  least. 

E.  The  heat  of  combustion  of  the  spent  shale  in  these  tests 
varies  from  12.58  to  21.85  per  cent  of  that  of  the  raw  shale  from 
which  it  is  derived,  and  averages  17.42  per  cent  of  it.    This  factor 
was  determined  by  multiplying  weight  of  spent  shale  from  one 
gram  of  raw  sfaale  by  the  heat  of  combustion  of  the  spent  shale. 
(See  Table  IV.) 

Example:  Heating  value  of  one  ton  of  oil-shale  yielding  50 
gallons  of  oil  per  .ton  =  10,660,000  B.  T.  U. 

10,660,000  B.  T.  U.  X  0.1742  =  1,858,000  B.  T.  U.  (Fuel 
value  of  spent  shale  from  one  ton  of  raw  50-gallon  shale.) 

F.  The  heat  of  combustion  of  the  oil  recovered  from  the  shales 
examined  varied  from  62.45  to  74.40  per  cent  of  the  heat  value  of 
the  shale  from  which  it  was  recovered,  and  averaged  67.06  per  cent 
of  it.    Tables  III  and  IV  indicate  how  this  factor  varies  and  how  it 
was  derived. 

Example:  Heating  value  of  one  ton  of  50-gallon  oil-shale  = 
10,660,000  B.  T.  U. 

10,660,000  X  0.6706  ==  7,148,000  B.  T.  U.  (Heating  value  of 
oil  obtained  from  one  ton  of  this  shale.) 

G.  The  heat  of  combustion  of  the  gas  obtained  from  the  shales 
used  in  these  tests  varied  from  9.00  to  18.10  per  cent  of  the  heat 
value  of  the  shale  from  which  it  was  obtained,  and  averaged  15.52 
per  cent  of  it.    Table  IV  also  indicates  how  this  factor  varies  among 
the  different  samples  examined. 

Example:  Heating  value  of  one  ton  of  50-gallon  oil-shale  = 
10,660,000  B.  T.  U. 

10,660,000  X  0.1552  =  1,654,000  B.  T.  U.  (Heating  value  of 
gas  obtained  from  one  ton  of  this  shale.) 

In  none  of  the  tests  reported  in  this  paper  was  gas  production 
forced  to  its  limit.  If  the  shales  had  been  heated  to  a  higher  tem- 
perature, or  held  at  the  maximum  temperature  reached  for  a  longer 
time,  a  greater  quantity  of  gas  would  have  been  recovered,  and  the 


.    CO-OPERATIVE  OIL-SHALE  LABORATORY  17 

heating  value  of  the  gas  produced  would  be  a  greater  percentage  of 
the  heat  value  of  the  raw  shale  than  is  indicated  above.  Such  gain 
by  the  gas  would  be  at  the  expense  of  the  spent  shale,  whose  weight 
and  total  heating  value  would  become  less  as  gas  production  reached 
a  maximum. 

Considering  the  diversity  of  the  samples  tested  as  to  physical 
and  chemical  nature,  oil  yield,  and  geologic  position,  it  is  reason- 
able to  believe  that  the  different  factors  developed  above  will  be  of 
very  general  application.  It  should  be  noted  again,  however,  that 
some  of  them  may  not  be  applicable  to  paper  shales  and  shales 
similar  to  them. 

Below  are  given  Tables  II,  III  and  IV,  aJJ  of  which  have  been 
developed  from  material  presented  in  Table  I  and  the  above  discus- 
sion. Following  these  is  Table  V  which  gives  data  on  fuel  values 
of  different  fuels  for  use  in  making  comparisons.  Table  II  pre- 
sents heat  values  necessary  for  use  in  calculating  heat  balances; 
Table  III  shows  the  actual  distribution  of  the  heat  value  of  the  raw 
shale  among  its  combustible  products;  and  in  Table  IV  the  per- 
centages of  the  total  heat  values  of  the  shales  examined,  appearing 
in-  spent  shale,  oil  and  gas,  are  given  as  well  as  average  values. 

TABLE  II. 

FACTORS  NECESSARY  FOR  CALCULATING  HEAT 
BALANCES. 


Sample  No. 

1 

2 

3 

4 

5 

6 

Weight  fresh  shale  (grams)  

1 

1 

1 

1 

1 

1 

Distillation  loss,   ner  cent  

8.15 

16.10 

20.80 

22.90 

37.70 

39.80 

Weight   spent   shale    (grams)  

0.918 

0.839 

0.792 

0.771 

0.623 

0.602 

Heat    of    combustion    spent    shale, 

Calories    per    gram1  

2136 

452 

473 

600 

1024 

924 

Heat  combustion  spent  shale  from 

1  gram  shale,  calories  

122 

380 

374 

463 

638 

557 

Oil   yield    (cc.    per   Ib.)  

19.0 

53.2 

70.0 

81.0 

143.0 

144.5 

Old  yield   (cc.  per  gram)  

0.0418 

0.117 

0.154 

0.178 

0.315 

0.518 

Specific  gravity  oil  at  15.5°  C  

0.880 

0.913 

0.919 

0.917 

0.888 

0.908 

Oil  yield   (gram  per  gram)  

0.0368 

0.1P7 

0.1415 

0.163 

0.282 

0.289 

Heat  combustion   oil,   calories   per 

gram1    7  

10400 

10914 

10400 

10200 

10142 

10495 

Heat  of  combustion   oil   from   one 

gram   of   shale,   calories  

383 

1090 

1470 

1661 

2860 

3180 

1  To  change  calories  per  gram  to  B.  T.  U.  per  pound,  multiply  by  1.8. 

2  Calculated  from  average  per  cent  heat  value  in  spent  shale  (see  Table  I). 

TABLE  III. 

HEAT  DISTRIBUTION. 
In  One  Gram  Fresh  Shale  and  Products  Obtained  from  It. 

Sample  No.  123456 

Heat   combustion   fresh   shale,   calories....  573  1744  2250  2460  3845  4430 

Heat  combustion  spent  shale,  calories1.-  2122  380  374  463  638  557 

Heat   combustion   oil 383  1090  1470  1661  2860  3180 

Heat     combustion      gas,      by      difference 

(calories)3   68  274  406  336  347  698 

Sum  of  heat  values  of  products,  calories  573  1744  2250  2460  3845  4430 

1  Weight   of  spent   shale    X    its   thermal  value    =    gram   calories   in   spent 
shale. 

2  Calculated  from  averages. 

3  See  pages  16  and  19. 


18 


SHORT  PAPERS  PROM  THE 


TABLE  IV. 
PERCENTAGE  HEAT  DISTRIBUTION. 


Sample  No. 

1 

2 

3 

4 

5 

6 

Av. 

Average 

Spent 
Shale 
Shale 
Total 

shale.... 
oil  

gas2  .... 

Per 

cent 
U7.29 
68.28 
14.43 
100.00 

Per 

cent 
21.85 
62.45 
15.70 
100.00 

Per 

cent 
16.60 
65.30 
18.10 
100.00 

Per 

cent 
18.80 
67.50 
13.70 
100.00 

Per 

cent 
16.60 
74.40 
9.00 
100.00 

Per 

cent 
12.58 
71.77 
15.65 
100.00 

Per 

cent 
17.29 
68.28 
14.43 
100.00 

exclud- 
ing No.  5 
17.42 
67.06 
15.52 
100.00 

1  Calculated  from  corresponding  averages  this  table. 

2  By  difference. 


TABLE  V. 

HEATING  VALUES  OF  SHALE  AND  SHALE  PRODUCTS 
COMPARED  WITH  OTHER  FUELS. 


No.  tons  needed  to  equal 

1  ton 
1  ton        bitum.  coal 


lignite 
Heat  of  combustion    6800  B.T.U. 
B.  T.  U.       heating 
Cal.  per  gm.    per  Ib.           value 

of  12500 
B.  T.  U. 
heating 
value 

Solid: 
Fresh    shale,      25    gal. 
Fresh    shale,      50    gal. 
Fresh    shale,      75    gal. 
Fresh   shale,    100    gal. 
Spent    shale,      25    gal. 
Spent   shale,      50    gal. 
Spent    shale,    75    gal. 
Spent   shale,    100    gal. 
Lignite 

oil 
oil 
oil 
oil 
oil 
oil 
oil 
oil 

per 
per 
per 
per 
per 
per 
per 
per 

ton       1482 
ton        2962 
ton        4440 
ton        5935 
ton          352 
ton          705 
ton        1055 
ton        1409 
3526-3994 

2665 
5330 
7995 
10660 
633 
1267 
1900 
2535 
6347-7189 
8761-10307 
10958-14134 
12577-13351 
12600 

18387 
18709 
19280 
19410 
19610 

2.55 
1.28 
0.851 
0.638 
10.73 
5.36 
3.58 
2.68 

4.69 
2.34 
1.56 
1.17 
19.75 
9.87 
6.58 
4.93 

Peat  (air  dried) 

4867-5726 

Coal      bituminous 

6088-7852 

Coal     anthracite 

—.6987-7417 
7000 

Coke 

Liquid: 
Shale  oil    sp    gr    0  917 

10215 

Shale  oil    sp    gr    0  880 

10400 

Fuel  oil    sp    gr    0.903 

10710 
.  .     .      10790 

Fuel  oil    sp    gr    0.880 

Fuel   oil.   st>.   err.   0.853.. 

10905 

Gaseous:  per  cu.  ft. 

Shale   gas,    early   stages1 A     482.0 

Shale  gas,  oil  15  to  90  per  cent  off1 B      976.0 

Shale  gas,  oil  90  to   100  per  cent  off1 C     526.0 

Shale   gas,    oil    all    off1 D     213.0 


No.  cu.  ft.  shale  gas  to 
equal  1  cu.  ft.  other  gas 


Natural  gas2              

.  ..1000 

A 

2.08 

B 

1.03 

C 

1  90 

D 
4  70 

Oil  gas2 

634 

1  32 

0  65 

1  21 

2  98 

Coal  gas2       

683 

1.42 

0.70 

1.30 

3.20 

153 

0  32 

0  16 

0  29 

0  72 

"Blue"  water  gas2 

322 

0.67 

0  33 

0  61 

1  51 

Obtained  by  dry  destructive  distillation  in  batch  retort;  efficiency  of  gas 
scrubbing    doubtful. 
2Average  values. 

In  the  discussion  under  paragraphs  E,  F,  and  G,  certain  fac- 
tors were  presented  by  means  of  which,  if  the  heat  value  of  a  sam- 
ple of  shale  is  known,  the  heating  value  of  its  products — gas,  oil, 


CO-OPERATIVE  OIL-SHALE  LABORATORY  19 

and  spent  shale — can  be  calculated.  These  factors  represent  the 
percentage  of  the  total  heating  value  of  the  raw  shale  appearing  in 
each  of  the  products,  and  as  can  be  noted  in  Table  IV,  the  per- 
centage of  the  original  heating  value  of  the  shale  found  in  the  gas 
is  determined  by  difference  from  100  per  cent,  as  the  heating  values 
of  the  shale,  oil,  and  spent  shale  have  been  experimentally  deter- 
mined. On  first  impression,  it  would  appear  that  the  sum  of  the 
heat  values  of  the  products  of  oil-shale  should  equal  the  heat  value 
of  the  raw  shale,  but  this  does  not  necessarily  follow. 

As  a  matter  of  fact  the  percentage  distribution  of  heating 
values,  as  shown  in  Table  IV,  applies  very  well  for  shales  yielding 
up  to  50  gallons  of  oil  per  ton,  but  for  richer  shales  experiments  in 
which  the  actual  heating  values  of  shale  gas  were  determined,  have 
indicated  that  the  percentages  representing  heating  value  distribu- 
tion must  be  somewhat  modified  to  obtain  fuel  values  for  the  spent 
shale  and  shale  gas  that  are  consistent  with  actually  observed  values.  * 
It  has  been  determined  by  experience  that  the  following  distribu- 
tion of  the  heating  value  of  the  raw  shale  among  its  products  agrees 
closely  with  observed  values  for  shales  of  different  richness : 

(If  the  total  heat  value  of  the  raw  shale  is  found  from  the 
formula:  106.6  X  oil  yield  in  gallons  per  ton  =  B.T.U.  per  pound 
of  shale.)  (See  page  16.) 

Up  to  50  gals.  50  to  80  gals.  80  to  100  gals. 

For  shales  yielding                                  on  per  con  oil  per  ton  oil  per  ton 
Percentage  of  total  heating  value  of 
raw   shale  found — 

In  oil  65.00  65.00  65.00 

In    spent     shale 18.65  15.00  11.00 

In   gas  15.35  16.00  16.00 

Percentage    unaccounted   for 1.00  4.00  8.00 

The  figures  shown  in  the  first  column  are  rounded  averages 
for  those  shales  discussed  in  this  paper  which  yielded  up  to  50 
gallons  of  oil  per  ton,  and  it  is  believed  that  they  may  be  applied 
without  serious  error.  The  values  given  in  the  other  columns  have 
been  somewhat  arbitrarily  chosen  from  results  on  rich  shales 
not  reported  in  this  paper.  As  most  shales  which  will  be  com- 
mercially worked  do  not  usually  yield  over  50  gallons  of  oil  to 
the  ton,  it  was  not  thought  worth  while  to  spend  any  great 
amount  of  time  in  determining  factors  for  richer  shales. 

It  is  interesting  to  consider  what  becomes  of  that  part  of  the 
heating  value  of  the  raw  shale  designated  as  "unaccounted  for" 
when  the  shales  are  distilled.  It  is  entirely  possible  that  there 
have  been  high  distillation  losses  in  the  distillation  of  the  richer 
shales,  which  may  not  have  been  observed,  but  the  writers  do 
not  believe  this  to  be  the  case.  The  decomposition  of  oil-shale 
into  its  products  is  a  thermo-chemical  process,  and  it  seems  most 
likely  that  the  heat  unaccounted  for  represents,  in  a  measure  at 
least,  the  heat  of  reaction  of  the  distillation  process.  The  heat 
of  reaction  of  the  process  undoubtedly  differs  with  different 
shales,  and  with  the  same  shales  when  they  are  distilled  under 
different  thermal  conditions,  thereby  producing  different  end 
products. 


20  SHORT  PAPERS  FROM  THE 

SUMMARY. 

The  results  of  the  work  presented  in  this  paper  make  it  pos- 
sible to  draw  the  following-  conclusions: 

1.  There  is  no  mathematical  relationship  between  the  spe- 
cific gravity  of  an  oil-shale  and  the  amount  of  oil  yielded  by  it. 
The  idea  that  shales  of  low  specific  gravity  yield  much   oil,   if 
used  at  all,  must  be  applied  with  caution. 

2.  The  ignition  loss  of  an  oil-shale  cannot  properly  be  used 
in  estimating  the  amount  of  oil  the  shale  will  yield. 

3.  The  heat  of  combustion  of  an  oil-shale  is  a  fairly  accurate 
indicator  of  the  amount  of  oil  the  shale  will  yield,  and,  conversely, 
the  oil  yield  is  a  reliable  indicator  of  the  heat  value  of  the  shale 
as  a  fuel. 

4.  The  heat  value  per  gram  of  spent  shales  apparently  tends 
to  approximate  a  constant  percentage  of  the  heat  value  per  gram 
of  the  shales  from  which  they  were  formed,  rather  than  a  con- 
stant average  heat  value,  when  the  shales  are  retorted  under 
constant   conditions.     For   the   conditions   of  retorting   used   in 
these  experiments,  this  percentage  is  23.19. 

5.  In  the  experiments  reported  in  this  paper,  the  amount 
of  heat  recoverable  in  the  shale  oil  tends  to  approximate  a  definite 
percentage  of  the  heat  of  combustion  of  the  original  shale.    For 
the  conditions  of  retorting  used  in  these  experiments  this  per- 
centage is  68.28. 

If,  as  is  here  indicated,  only  68.28  per  cent  of  the  original 
fuel  value  of  the  shale  is  contained  in  the  oil  recovered  by  dry 
destructive  distillation,  it  seems  highly  desirable,  from  a  view- 
point of  national  economy,  that  both  the  spent  shale  and  shale 
gas  be  used  as  fuel  to  the  fullest  extent.  When  the  fuel  values 
of  these  latter  products  are  considered,  however,  it  is  doubtful 
if  such  use  will  always  be  the  most  profitable  from  a  financial 
standpoint. 

6.  For  fairly  approximate  work  it  can  be  taken  that  the  oil 
yield  of  a  shale  (as  determined  by  assay)  in  gallons  per  ton,  mul- 
tiplied by  the  factor  106.6  equals  the  gross  heat  of  combustion 
of  the  shale  in  B.T.U.  per  pound: 

7.  To  obtain  the  net  heat  value  the  factor  106.6  may  be  cor- 
rected as  follows: 

(a)  For  every  gallon  of  water  per  ton  which  is 
vaporized,  subtract  4.66  from  the  106.6  factor. 

(~b)  For  every  degree  Fahrenheit  above  212°  F. 
(boiling  point  water)  each  gallon  of  vaporized  water 
(steam)  is  raised  in  temperature  before  its  discharge,  a 
further  subtraction  of  0.002  should  be  made  from  the 
106.6  factor. 

Example:  A  shale  assaying  50  gallons  oil  and  2  gal- 
lons water  per  ton,  is  used  as  fuel  where  flue  gas  exit 
temperature  is  612°  F. 


CO-OPERATIVE  OIL-SHALE  LABORATORY  21 

Gross  heating  value  is  50  X  106.6  =  5330  B.T.U.  per  pound. 
Net  heating  value  is  50  X   [106.6  --  (2  X  4.66)  -  -  (400 
X  0.002)]  =  50  X  96.48  =  4820  B.T.U.  per  pound. 

8.  For  shales  yielding  up  to  50  gallons  of  oil  per  ton  the 
following  relations  can  be  used  for  close  approximations : 

(a)  Heat  value  of  raw  shale  multiplied  by  0.1742 
equals  the  total  heat  value  in  B.T.U.  of  the  spent  shale 
derived  from  it. 

(~b)  Heat  value  of  raw  shale  multiplied  by  0.6706 
equals  the  total  heat  value  in  B.T.U.  of  the  oil  derived 
from  it. 

(c)  Heat  value  of  raw  shale  multiplied  by  0.1552 
equals  the  total  heat  value  in  B.T.U.  of  the  gas  produced 
from  it. 

These  relationships  hold  only  for  dry  destructive  distillations 
under  the  conditions  used  in  these  tests.  For  shales  richer  than 
those  yielding  50  gallons  of  oil  to  the  ton,  the  above  factors  must 
be  modified  as  indicated  on  page  19. 


22  SHORT  PAPERS  FROM  THE 


OBSERVATIONS  ON  SHALE  GAS. 

Frequent  mention  has  been  made  of  the  possibility  of  supply- 
ing all  or  part  of  the  heat  necessary  to  retort  oil-shale  by  burning 
the  uncondensible  gas  under  the  retort  as  fuel.  This  paper  has 
been  prepared  to  present  the  findings  with  regard  to  the  feasi- 
bility of  this  plan. 

In  a  paper  on  the  "Fuel  Values  of  Oil-Shales  and  Oil-Shale 
Products"  (see  Table  IV)  the  writers  show  that  from  9.0  to 
18.1  per  cent  of  the  heat  value  of  the  shale  is  represented,  after 
retorting  by  dry  destructive  distillation,  by  the  uncondensible 
gases.  The  average  for  the  shales  examined  was  about  15.0  per 
cent.  From  this  it  is  evident  that  the  total  heat  value  obtainable 
from  uncondensible  gases  varies  much  with  different  shales.  It 
will  also  differ  with  different  conditions  of  retorting. 

The  tests  described  below  show  that  the  heating  value  of  the 
gas  also  varies  more  or  less  according  to  time  at  which  the  gas 
is  formed  with  reference  to  oil  production.  This  statement  ap- 
plies also  to  the  chemical  composition  of  the  gas.1 

In  Table  VI  the  results  tabulated  under  Shale  No.  10  are  the 
average  of  those  obtained  in  four  retort  tests  on  75-pound  samples 
of  shale  assaying  42.7  gallons  of  oil  per  ton;  those  under  Shale 
No.  11  are  an  average  of  observations  made  on  four  retort  tests 
using  75  pounds  of  shale  yielding,  on  assay,  37  gallons  of  oil  per 
ton;  and  those  under  Shale  No.  12  are  the  observations  made  on 
a  single  retort  test  using  75  pounds  of  shale  yielding,  on  assay, 
28  gallons  of  oil  per  ton. 


1  During  tests  on  shale  samples  Nos.  11  and  12,  Table  VI,  all  gas  was 
scrubbed,  an  average  of  0.115  gallons  of  gasoline  being  absorbed  from  1000.0 
cubic  feet,  as  follows: 

Test  No.  5.     36.75  cc.  from  132.8  cu.  ft.  or  0.0728  gals,  per   1000  cu.  ft. 

Test  No.   6.     23.00  cc.  from     36.3  cu.  ft.  or  0.167     gals,  per  1000  cu.  ft. 

Test  No.  7.     46.00  cc.  from     81.5  cu.  ft.  or  0.149     gals,  per  1000  cu.  ft. 

Test  No.   8.     26.00  cc.  from     93.5  cu.  ft.  or  0.0733  gals,  per  1000  cu.  ft. 

There  is  a  possibility  that  the  scrubbing  was  somewhat  incomplete  on 
account  of  a  too  rapid  gas  flow. 

The  gas  samples  referred  to  were  produced  in  the  course  of  shale  retort- 
ing tests  made  in  the  United  States  Bureau  of  Mines  and  State  of  Colorado 
co-operative  oil-shale  retort  at  Boulder,  Colorado.  Briefly,  this  retort  is  an 
externally  gas  fired,  horizontal,  rotary,  iron  cylinder  with  a  pyrometer  well 
in  one  end  and  the  vapor  exit  in  the  other.  The  vapors  are  drawn  through 
an  air-cooled  and  a  water-copied  condenser,  then  pumped  through  water  and 
a  light  "straw"  oil.  On  leaving  the  oil  scrubber  the  gases  are  metered.  The 
heating  value  of  the  gas  is  next  determined  with  a  Junkers  calorimeter  set. 
Samples  are  collected  over  water  for  analysis  by  a  standard  portable  Williams 
Orsat  pipette. 


CO-OPERATIVE  OIL-SHALE  LABORATORY 


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24  SHORT  PAPERS  FROM  THE 

CONCLUSIONS. 

The  following  conclusions  may  be  reached  as  a  result  of  the 
experimental  evidence  presented  in  Table  VI  and  later  work, 
results  of  which  were  unavailable  for  presentation  in  detail  in 
this  bulletin. 

1.  In  general  the  thermal  value  of  the  gas  rises  with  the 
temperature  at  which  the  gas  was  formed,  until  some  90  per  cent 
of  the  oil  obtainable  has  been  distilled  from  the  shale. 

2.  Before  15  per  cent  of  the  obtainable  oil  is  distilled  from 
the  shale,  the  heat  value  of  the  gas  is  approximately  482  B.T.U. 
per  cubic  foot. 

3.  After  15  per  cent  of  the  possible  oil  has  been  recovered, 
and  until  90  per  cent  is  obtained,  the  thermal  value  of  the  gas 
rises  to  an  average  of  976  B.T.U.  per  cubic  foot. 

4.  After  90  per  cent  of  the  obtainable  oil  has  been  recovered, 
the  average  thermal  value  of  the  gas  is  about  526  B.T.U.  per 
cubic  foot,  or  very  similar  to  that  obtained  during  the  time  of 
producing  the  first  15  per  cent  of  the  oil. 

5.  After  all  the  oil  has  been  yielded  by  the  shale,  the  thermal 
value  of  the  gases  formed  drops  to  a  value  of  about  213  B.T.U. 
per  cubic  foot,  and  probably  remains  between  200  and  300  B.T.U. 
until  gases  cease  to  be  evolved. 

6.  In  the  early  stages  of  retorting  there  seems  to  be  no 
definite  relation  between  the  thermal  value  of  the  gas  and  the  rate 
of  oil  production.     This  seems  to  hold  true  until  after  90  per 
cent  of  the  oil  yield  is  obtained,  after  which  time  the  heating 
value  of  the  gas  seems  to  fall  off,  roughly  as  the  rate  of  oil  pro- 
duction decreases. 

7.  There  is  apparently  no  connection  between  the  rate  of 
gas  production  and  its  heating  value,  or  between  the  rate  of  tem- 
perature rise  just  before  the  calorific  determination,  and  the  value 
of  the  latter. 

It  was  intended  that  a  gas  sample,  for  analysis,  should  be 
collected  during  or  immediately  after  each  calorific  value  test. 
The  samples  were  collected  but  due  to  breakage  of  apparatus  it 
was  necessary  to  delay  some  of  the  analyses  until  their  results 
were  manifestly  incorrect,  and  therefore  only  three  are  sub- 
mitted. These  three  are  results  obtained  on  freshly  collected 
samples  and  are  therefore  believed  to  actually  represent  the  gases 
as  they  were  produced. 

The  exact  conditions  of  the  tests,  so  far  as  the  apparatus 
permitted  their  observation  at  the  time  of  sampling  the  gases, 
together  with  the  analyses  of  the  gases,  are  shown  in  Table  VII. 
Average  analyses  of  various  other  natural  and  artificial  gases 
are  also  included  in  the  table  for  comparison. 

The  authors  appreciate  that  it  is  unjustifiable  to  draw  con- 
clusions from  the  results  of  so  few  analyses.  The  analyses  are 
appended,  however,  to  show  the  nature  of  the  work  under  way 
and  to  give,  at  least,  a  preliminary  idea  of  the  nature  of  the  shale 
gas  obtained  under  the  conditions  prevailing  in  the  experimental 
work. 


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MAP  OP  NORTHWESTERN   COLORADO 

The  shaded  areas  show  the  extent  of  the  Green  River  formation    in  which 
the  workable  beds  of  oil  shale  occur. 


CO-OPERATIVE  OIL-SHALE  LABORATORY  27 

RESULTS  OF  NINE  OIL-SHALE  RETORTING 

TESTS. 


INTRODUCTION. 

The  studies  of  factors  affecting  the  retorting  of  oil-shale 
undertaken  by  the  United  States  Bureau  of  Mines  and  State  of 
Colorado  in  April,  1920,  have  progressed  to  such  an  extent  that 
the  publication  of  results  of  preliminary  tests  seems  justified. 
This  paper,  therefore,  submits  nine  curves,  and  a  summarized 
table,  from  which  the  curves  were  derived,  showing  relations 
between  temperature,  oil  production,  gas  production,  thermal 
value  of  gas,  gas  sampling,  and  in  some  cases,  water  production. 
It  is  pointed  out  that  these  tests  were  made  with  a  horizontal 
rotary  retort,  and  that  the  shales  were  dry  distilled,  no  steam  or 
other  gas  being  used  in  the  retort.  The  results  presented  here- 
with probably  apply  only  for  the  retorting  conditions  adhered 
to  in  the  respective  tests. 

EXPERIMENTAL  PLAN. 

The  retorting  tests  at  the  Boulder  Co-operative  Oil-Shale 
Laboratory  are  planned  to  follow  a  definite  program.  A  retort- 
ing test  is  made  under  a  definite  set  of  conditions  and  then  the 
products  are  examined,  so  that  the  results  of  certain  applied  con- 
ditions may  be  known  before  the  next  test  is  begun.  The  pur- 
pose of  the  study  is  to  determine  those  conditions  most  favorable 
for  producing  the  highest  yields  of  the  best  grade  of  oil  from  oil- 
shales.  Therefore  many  variable  conditions  of  retorting  must  be 
studied,  and  their  effects  on  quantity  and  quality  of  products 
determined.  Such  a  study  will  require  a  considerable  period  of 
time  for  completion,  as  the  effects  of  the  following  variable  fac- 
tors must  be  determined : 

A.  Nature  of  the  shale. 

B.  Rate  of  rise  of  retorting  temperature. 

C.  Size  of  shale  particles  retorted. 

D.  Actual  temperature  range  used  in  retorting. 

E.  Use  of  steam  and  other  gases,  at  various  temperatures 
and  pressures  and  in  different  amounts. 

F.  Use  of  pressures  above  or  below  atmospheric. 

G.  Material  used  in,  and  design  of  retorting  equipment. 
H.     Means  by  which  heat  is  applied  to  the  shale. 

I.  Time  retorting  products  are  in  contact  with  heated  sur- 
faces, or  in  other  words,  velocities  of  vapors  through  and  from 
the  retort. 

In  the  studies  under  way  each  variable  is  changed  according 
to  a  regular  program  until  best  results  are  obtained,  then  another 
variable  is  changed,  the  idea  being  that  ultimately  the  work  will 
enable  definite  conclusions  to  be  drawn  as  to  the  proper  com- 
bination of  conditions  necessary  to  produce  best  results. 


28  SHORT  PAPERS  FROM  THE 

DESCRIPTION  OF  EXPERIMENTAL  WORK. 

The  material  presented  in  this  paper  deals  with  the  first  nine 
retorting  tests  made  in  the  Boulder  laboratory,  and  may  be  con- 
sidered a  preliminary  study.  When  the  apparatus  was  first 
erected  it  was  necessary  to  determine  its  flexibility,  its  behavior 
with  shales  of  different  richness,  and  its  ability  to  operate  under 
pressures  different  from  atmospheric,  before  a  definite  program  of 
work  could  be  undertaken.  Therefore,  in  the  first  four  distilla- 
tions shown  in  Table  VIII  and  in  Curves  1  to  4,  are  results  ob- 
tained while  the  retorting  equipment  was  being  tried  out  and 
the  operators  familiarizing  themselves  with  the  apparatus.  Tests 
Nos.  5  to  8  inclusive  represent  the  first  four  tests  undertaken  in 
the  plan  to  determine  the  effects  of  various  rates  of  heating,  all 
other  conditions  being  kept  as  nearly  constant  as  possible.  Test 
No.  9  represents  the  results  on  a  lean  shale  which  was  examined 
to  secure  information  not  particularly  in  line  with  the  plan  of 
the  program. 

Since  the  data  presented  in  this  paper  were  obtained,  many 
more  retorting  tests  have  been  made,  both  in  the  Boulder  Co- 
operative Laboratory  and  at  the  Intermountain  Experiment  Sta- 
tion of  the  Bureau  of  Mines,  which  is  carrying  on  similar  investi- 
gations, a.s  has  been  noted.  The  study  is  by  no  means  complete, 
and  cannot  be  expected  to  be  complete  for  considerable  time. 
Good  progress  has  been  made,  however,  and  in  a  short  time  it  will 
be  possible  to  present  a  paper  giving  results  of  many  more  re- 
torting tests  with  complete  examinations  of  the  products  made 
in  each.  The  present  paper  will  indicate  the  trend  of  the  work 
and  draw  some  interesting  and  valuable  conclusions. 

It  will  be  noted  that  the  shale  used  in  the  first  four  tests 
yielded  on  assay  42.7  gallons  of  oil  to  the  ton,  but  as  it  was  not 
possible  to  secure  a  large  supply  of  this  grade  of  shale  at  a  rea- 
sonable cost,  it  was  decided  to  carry  out  the  investigation  with 
the  shale  used  in  tests  Nos.  5  to  8  inclusive.  A  large  quantity  of 
this  shale  has  been  secured  and  it  is  now  being  used.  It  will  also 
be  used  in  future  work. 

Retort  temperatures  given  in  the  table  and  figures  were  de- 
termined by  means  of  a  thermo-couple  placed  in  the  center  of 
the  retort  along  the  horizontal  axis.  It  is  known  that  tempera- 
tures along  the  line  of  the  horizontal  axis  of  the  retort  are  practi- 
cally uniform,  but  it  is  likely  that  temperatures  so  determined 
are  considerably  less  than  the  actual  temperatures  of  the  shale 
distilling  in  the  retort.  The  retort  is  now  being  equipped  so  that 
the  actual  shale  temperature  may  be  determined. 

In  all  cases  75  pounds  of  shale  were  charged  into  the  retort, 
making  a  layer  3!/2  inches  thick  at  its  greatest  depth  in  the  retort. 
The  shale  was  crushed  to  pass  a  2-inch  opening,  and  all  particles 
smaller  than  14  incn  were  screened  out. 


CO-OPERATIVE  OIL-SHALE  LABORATORY 


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Figure  1. — Graphic  Representation  of  Retorting  Test  No.  1.  Date:  May  20, 
1920.  Colorado  Oil  Shale.  Assay,  42.7  gallons  oil  per  ton.  Average  heating 
rate,  3.88°  F.  per  minute.  Pressure,  atmospheric.  Oil  curve  not  corrected  for 
•water  in  suspension;  see  Table  VIII  and  page  41.  Total  water  in  suspension 
this  run,  431  cc.,  or  8.26  per  cent. 


CO-OPERATIVE  OIL-SHALE  LABORATORY 


31 


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4OOO 


Piffure  2. — Representation  of  Retorting  Test  No.  2.  Date:  May  25,  1920. 
Colorado  Oil  Shale.  Assay,  42.7  gallons  oil  per  ton.  Average  heating  rate, 
6.12°  F.  per  minute.  Pressure,  atmospheric.  A  Oil  is  oil  condensed  in  air 
cooled  condenser.  B  Oil  is  oil  condensed  in  water  cooled  condenser.  Oil 
curves  not  corrected  for  water  in  suspension.  See  Table  VIII  and  page  41. 
Total  water  in  suspension  this  run,  486  cc.,  or  8.26  per  cent. 


32 


SHORT  PAPERS  FROM  THE 


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Figrire  3. — Graphic  Representation  of  Retorting-  Test  No.  3.  Date:  May 
29,  1920.  Colorado  Oil  Shale.  Assay,  42.7  gallons  oil  per  ton.  Average  heat- 
ing rate,  6.82°  F.  per  minute.  Pressure,  reduced,  as  indicated.  A  Oil  is  oil 
condensed  in  air  cooled  condenser.  B  Oil  is  oil  condensed  in  water  cooled 
condenser.  Oil  curves  not  corrected  for  water  in  suspension.  S^e  Table  VIII 
and  page  41.  Total  water  in  suspension  this  run,  371  cc.,  or  8.26  per  cent. 
(1)  Calorific  value  of  gas,  482  B.  t.  u.;  (2)  Calorific  value  of  gas  492  B  t  u  • 
(3)  Meter  broke. 


CO-OPERATIVE  OIL-SHALE  LABORATORY 


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Pig-ure  4. — Graphic  Representation  of  Retorting-  Test  No.  4.  Date:  Au- 
gust 20,  1920.  Colorado  Oil  Shale.  Assay,  42.7  gallons  oil  per  ton.  Average 
heating  rate,  8.16°  F.  per  minute.  Pressure,  reduced  as  indicated.  A  Oil  is 
oil  condensed  in  air  cooled  condenser.  B  Oil  is  oil  condensed  in  water  cooled 
condenser.  Oil  curves  not  corrected  for  water  in  suspension.  See  Table  VIII 
and  page  41.  Total  water  in  suspension  this  run,  266  cc.,  or  6.93  per  cent. 
(1)  Calorific  value  of  gas,  1045  B.  t.  u. 


34 


SHORT  PAPERS  PROM  THE 


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Pigure  5. — Graphic  Representation  of  Retorting  Test  No.  5.  Date:  Sep- 
tember 30,  1920.  Colorado  Oil  Shale.  Assay,  37.0  gallons  oil  per  ton  \verage 
heating  rate,  3.56°  F.  per  minute.  Pressure,  atmospheric.  A  Oil  is  oil  con- 
densed in  air  cooled  condenser.  B  Oil  is  oil  condensed  in  water  cooled  con- 
denser. Oil  curves  not  corrected  for  water  and  suspension.  See  Table  VIII 
and  page  41.  Total  water  in  suspension  this  run,  573  cc.,  or  13  9  per  cent 
(1)  Calorific  value  of  gas,  274  B.  t.  u.  (2)  Gas  sample  taken.  (3)  Gas  sample 
taken.  (4)  Gas  sample  taken.  (5)  Calorific  value  of  gas,  141  B  t  u  (6)  Gas 
sample  taken. 


CO-OPERATIVE  OIL-SHALE  LABORATORY 


35 


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Figure  6. — Graphic  Representation  of  Retorting  Test  No.  6.  Date:  Octo- 
ber 9,  1920.  Colorado  Oil  Shale.  Assay,  37.0  gallons  oil  per  ton.  Average 
heating  rate,  3.49°  F.  per  minute.  Pressure  atmospheric.  A  Oil  is  oil  con- 
densed in  air  cooled  condenser.  B  Oil  is  oil  condensed  in  water  cooled  con- 
denser. Oil  curves  not  corrected  for  water  in  suspension.  See  Table  VIII, 
and  page  41.  Total  water  in  suspension  this  run,  413  cc.,  or  9.18  per  cent. 
(1)  Heating  value  of  gas,  1,049  B.  t.  u.  Gas  sample  taken.  (2)  Heating  value 
of  gas,  843  B.  t.  u.  Gas  sample  taken.  (3)  Heating  value  of  gas,  285  B.  t.  u. 
Gas  sample  taken. 


36 


SHORT  PAPERS  FROM  THE 


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sooo    asoo     3000    3500     «?ooo 


PigTire  7. — Graphic  Representation  of  Retorting  Test  No.  7.  Date:  Octo- 
ber 13,  1920.  Colorado  Oil  Shale.  Assay:  37.0  gallons  oil  per  ton.  Average 
heating  rate,  3.46°  F.  per  minute.  Pressure,  atmospheric.  A  Oil  is  oil  con- 
densed in  air  cooled  condenser.  B  Oil  is  oil  condensed  in  water  cooled  con- 
denser. Oil  curves  not  corrected  for  water  in  suspension.  See  Table  VIII 
and  page  41.  Total  water  in  suspension  this  run,  418  cc.,  or  9.31  per  cent. 
(1)  Heating  value  of  gas,  708  B.  t.  u.  (2)  Heating  value  of  gas,  817  B.  t.  u. 


CO-OPERATIVE  OIL-SHALE  LABORATORY 


37 


KX>      SCO       <5OO       400       £OO       GOO        TOO       6OO       SOO       fOOO 


^fOO 


4000 


c.c-o/t 


Pig-lire  8. — Graphic  Representation  of  Retorting  Test  No.  8.  Date:  Octo- 
ber 15,  1920.  Colorado  Oil  Shale.  Assay,  37.0  gallons  oil  per  ton.  Average 
heating  rate,  3.36°  F.  per  minute.  Pressure,  atmospheric.  A  Oil  is  oil  con- 
densed in  air  cooled  condenser.  B  Oil  is  oil  condensed  in  water  cooled  con- 
denser. Oil  curves  not  corrected  for  water  in  suspension.  Se^  Table  VIII, 
and  page  41.  Total  water  in  suspension  this  run,  318  cc.,  or  7.56  per  cent. 

(1)  Heating  value  of  gas,  994  B.  t.  u.      (2)  Heating  value  of  gas,  1,126  B.  t.  u. 

(3)   Heating  value  of  gas,  741  B.   t.   u.     , 


38 


SHORT  PAPERS  FROM  THE 


TEMPERATURE  <—  Y^ 
JQO      BOO      300      *X>      *5DO      GOO      TOO     GOO       9OO      XXX?      //(%> 


300          /OOO 


3OOO      3SOO       3000      35OO      4OOO 
M44TE&. 


Fig-ore  9.— Graphic  Representation  of  Retorting  Test  No.  9.  Date:  Octo- 
ber 27,  1920.  Colorado  Oil  Shale.  Assay,  28.0  gallons  oil  per  ton.  Average 
heating  rate,  6.38°  F.  per  minute.  Pressure,  atmospheric.  A  Oil  is  oil  con- 
densed in  air  cooled  condenser.  B  Oil  is  oil  condensed  in  water  cooled  con- 
denser. Oil  curves  not  corrected  for  water  in  suspension.  See  Table  VIII, 
and  page  41.  Total  water  in  suspension  this  run,  313  cc.,  or  11.25  per  cent. 
(1)  Heating  value  of  gas,  312  B.  t.  u. 


CO-OPERATIVE  OIL-SHALE  LABORATORY  39 

DISCUSSION  OF  RETORTING  TESTS. 

As  has  been  mentioned,  the  first  four  tests  were  not  run  accord- 
ing to  any  definite  program,  and  so  many  variables  entered  into 
these  tests  that  it  is  impossible  to  draw  conclusions  as  to  the  effect 
of  any  one  variable.  In  tests  Nos.  5  to  8  all  conditions  were  held 
as  nearly  constant  as  possible. 

The  first  four  tests  were  made  with  the  retort  rotating  at  seven 
revolutions  per  minute.  This  rate  was  found  to  be  too  rapid,  as  it 
produced  a  decided  ball-mill  effect  on  the  shale.  Consequently  the 
rate  of  rotation  has  been  reduced  to  3.75  revolutions  per  minute, 
which  seems  to  be  quite  satisfactory,  and  was  adhered  to  in  the 
other  tests  reported.  This  rate  will  be  used  in  the  future. 

The  first  two  tests  were  made  under  atmospheric  pressure,  and 
it  was  noticed  that  a  certain  amount  of  dust  was  carried  over  into 
the.  condensing  system  and  pump.  In  tests  Nos.  3  and  4,  made 
under  vacuum,  carrying  over  of  the  dust  became  so  serious  that  a 
drum-head,  made  of  iron  screen  and  packed  with  steel  wool,  was 
placed  in  the  discharge  end  of  the  retort,  just  in  front  of  the  vapor 
outlet.  This  seems  to  prevent  trouble  due  to  dust,  but  as  the  screen- 
head  apparently  has  a  bad  effect  on  the  oil,  evidently  producing 
cracking,  it  may  be  necessary  to  remove  it.  With  the  slow  rate  of 
rotation  now  being  used  it  is  believed  that  the  use  of  the  screen- 
head  will  be  unnecessary,  unless  the  retort  is  operated  under  re- 
duced pressure. 

Tests  Nos.  3  and  4  were  made  under  vacuum,  as  may  be  noted 
in  Table  VIII.  Rather  unexpected  results  were  obtained.  It  was 
believed  that  a  higher  recovery  of  oil  and  a  smaller  amount  of  gas 
would  be  obtained  from  the  shale  under  reduced  pressure.  Entirely 
contrary  results  were  obtained.  Since  only  two  vacuum  tests  were 
made  it  is  difficult  to  account  for  this  fact,  and  no  attempt  is  made 
to  explain  it,  except  that  excessive  cracking  or  incomplete  conden- 
sation may  have  been  responsible  for  the  unexpected  results.  At 
the  proper  time  in  the  course  of  the  experiments  the  effects  of 
reduced  pressures  will  be  carefully  studied,  making  it  possible  to 
draw  conclusions.  The  vacuum  tests  made  indicate  that  the  retort 
can  be  operated  successfully  under  greatly  reduced  pressure  with- 
out leakage.  Tests  Nos.  3  and  4  indicate  also  that  the  shale  begins 
to  produce  oil  at  a  lower  temperature  under  reduced  pressure  than 
under  atmospheric  pressure. 

It  will  be  noted  in  Table  VIII  that  the  rate  of  heating  is  given 
as  real  average  rate  of  heating  and  also  in  terms  representing 
apparent  average  rate  of  heating.  The  first  takes  no  account  of  the 
time  when  temperatures  remained  constant  or  fell,  but  considers 
only  that  period  during  which  the  temperature  was. actually  rising 
and  the  total  gross  increase  of  temperature  during  that  time.  The 
second  is  obtained  by  dividing  the  total  net  temperature  rise  by 
the  number  of  minutes  required  during  the  test  to  reach  the  maxi- 
mum temperature.  It  will  be  noted  that  the  figures  representing 
these  two  calculated  rates  are  very  nearly  the  same  in  the  later 
tests,  but  the  earlier  ones  show  considerable  variation,  due  to  inex- 
perience with  the  apparatus. 


40  SHORT  PAPERS  FROM  THE 


CONCLUSIONS. 

Examination  of  Table  VIII  and  the  curves  indicates  the  fol- 
lowing : 

A.  Initial  temperatures1. 

The  evolution  of  gas  in  noticeable  quantity  commences  between 
200°  and  250°  F.,  and  usually  close  to  235°  F.  (113°  C.). 

Water  probably  starts  distilling  at  about  the  same  temperature 
as  the  gas  and  appears  as  condensed  water  from  the  condenser 
when  the  retort  temperature  is  about  325°  F.  (163°  C.). 

Oil  begins  to  flow  from  the  condenser  when  the  temperature  in 
the  center  of  the  retort  reaches  about  450°  F.  (232°  C.).  It  is 
noteworthy  that  the  shale  used  in  tests  Nos.  1  to  4  began  to  produce 
oil  at  a  lower  temperature  than  the  other  shales  used.  Vacuum 
reduced  the  initial  oil  production  temperature  considerably  (see 
tests  Nos.  3  and  4). 

B.  Range  of  production. 

Gas  production  will  continue  considerably  above  the  highest 
temperature  used  in  these  tests.  The  volume  will  probably  increase 
for  some  time,  and  its  heating  value  decrease.  (See  paper  on  shale 
gas,  page  24.) 

Water  is  produced  throughout  the  oil  production  range,  but 
above  500°  F.  (260°  C.)  the  water  is  usually  emulsified  with  the 
oil,  and  cannot  be  separated  by  gravity!  settling  at  ordinary  tem- 
peratures. 

The  average  range  for  oil  production  is  about  625°  F. 
(350°  C.),  all  of  it  being  distilled  off  at  a  temperature  between 
1100°  and  1150°  F.  (593°-621°  C.).  Nearly  all  the  oil  (about  96 
per  cent)  is  produced  before  the  temperature  reaches  900°  F. 
(482°  C.). 

C.  Yields. 

The  total  gas  yield  in  the  different  tests  varies  from  about 
1,000  cubic  feet  per  ton  of  shale  to  nearly  3,600  cubic  feet,  and  aver- 
aged 1,770  cubic  feet  per  ton.  In  no  case  was  gas  production  forced 
to  the  limit. 

The  oil  yields  show  a  considerable  variation  ranging  from  59 
to  89  per  cent,  based  on  assays.  No  gas  scrubbers  were  used  in 
tests  Nos.  1  to  4. 

Water  yields  vary  considerably,  as  different  parts  of  the  shale 
samples  contain  different  percentages  of  water.  In  some  of  the 
tests  reported  water  yields  are  higher  than  actual  yields  from  the 
shale,  as  it  is  often  necessary  to  clean  the  apparatus  with  steam  at 
the  end  of  the  run  to  remove  all  the  oil.  This  sometimes  introduces 
an  unmeasured  amount  of  water  into  the  results,  especially  if  the 
steam  and  condensed  oil  emulsify. 

1  See    footnotes,    Table    VIII,    on    temperature    measurement.      Particular 
emphasis  is  directed  to  the  position  of  the  pyrometer. 


CO-OPERATIVE  OIL-SHALE  LABORATORY  41 

Much  water  is  produced  in  emulsion  with  the  oil.  Oil  yields 
shown  in  Table  VIII  are  corrected  for  water  in  emulsion,  but  yield 
curves  in  Figures  1  to  9  are  not  so  corrected,  as  it  was  not  possible 
to  determine  the  percentage  of  water  in  emulsion  in  the  oil  as  the 
oil  accumulated  in  the  measuring  receiver.  Percentage  of  emulsi- 
fied and  suspended  water  is,  however,  indicated  on  the  curves. 

D.     Rate  of  temperature  rise. 

Under  this  heading  only  tests  Nos.  1  and  2,  and  5  to  8  inclu- 
sive, can  be  discussed,  for  reasons  above  presented.  It  will  be  noted 
that  the  rates  of  heating  used  do  not  vary  widely,  but  generally  it 
appears  that  a  greater  yield  of  oil  is  obtained  with  the  slower  rates 
of  heating.  The  effect  on  the  quality  of  the  oil  has  not  been  clearly 
established,  but  it  appears  that  oils  of  better  quality  are  produced 
at  slower  rates  of  heating.  It  has  been  noted  in  every  case  that 
when  very  rapid  rates  of  heating  were  employed,  the  oil  had  the 
odor  of  badly  cracked  oil. 

The  effect  on  gas  production  is  apparently  as  is  to  be  expected, 
that  is,  smaller  quantities  of  gas  are  produced  at  the  lower  rates 
of  heating. 

FUTURE  RETORTING  WORK. 

The  retorting  work  now  under  way  is  to  determine  the  effects 
of  several  variables  on  the  products  of  retorting  oil-shales.  The 
effect  of  different  rates  of  heating  are  being  studied  first,  and  tests 
are  now  being  made  with  rates  much  more  varied  than  reported  in 
this  paper.  It  has  been  suggested  that  a  uniform  rate  of  heating 
may  not  be  a  desirable  function  on  which  to  base  work  of  this  sort, 
and  that  a  uniform  rate  of  oil  production  would  be  better.  Theo- 
retically this  suggestion  has  much  merit  but  when  its  commercial 
applications  are  examined  it  would  seem  to  limit  certain  types  of 
retorts  by  greatly  complicating  their  structure,  if  indeed  it  does 
not  absolutely  bar  them.  Work  will  be  continued  using  different 
uniform  rates  of  heating  on  the  same  shale,  and  then  it  is  planned 
to  make  a  series  of  tests,  using  constant  oil  production  as  a  basis. 

After  the  most  favorable  heating  rate  has  been  determined  for 
the  particular  shale  under  examination,  other  factors  will  be  varied, 
as  mentioned  on  page  27.  It  is  particularly  desired  to  determine 
the  effects  of  different  sizes  of  shale  particles  on  the  products  made 
at  different  heating  rates.  Any  suggestions  and  data  bearing  on 
this  work  from  persons  interested  in  oil-shale  will  be  appreciated. 


42  SHORT  PAPERS  FROM  THE 


ANALYTICAL  DISTILLATION  OF  SHALE  OIL  FROM 
COLORADO  OIL-SHALE. 

INTRODUCTION. 

After  each  retorting  test  at  the  Boulder  Co-operative  Oil-Shale 
Laboratory,  samples  of  the  various  products  collected  during  the 
run  are  examined  in  the  laboratory.  An  analysis  is  made  of  the 
gas  evolved  during  retorting,  and  its  calorific  value  is  determined. 
Condensed  water  from  the  retort  condensers  is  examined  primarily 
to  determine  content  of  nitrogen.  Liquids  from  the  oil  and  water 
scrubbers  are  tested  for  content  of  gasoline  and  ammonia,  respect- 
ively. Spent  shale  from  the  retort  is  assayed  to  determine  com- 
pleteness of  retorting,  and  a  proximate  analysis  is  made  on  it. 
Finally  the  oil  recovered  during  the  run  is  fractionally  distilled, 
first  at  atmospheric  pressure,  and  then  under  reduced  pressure,  and 
the  fractions  are  examined. 

In  some  cases  one  overall  sample  of  the  oil  produced  during  the 
run  is  taken.  In  others  several  samples  are  taken  during  the  course 
of  the  distillation  of  the  shale.  Proper  examination  of  the  several 
samples  indicates  whether  the  oil  produced  from  the  shale  changes 
during  the  retorting  period. 

This  paper  presents  a  series  of  analyses  of  oils,  all  produced 
from  the  same  shale  during  the  same  retorting  test.  The  large 
horizontal  rotary  retort  was  charged  with  Colorado  oil-shale,  ob- 
tained near  DeBeque,  and  retorting  carried  out. in  the  usual  man- 
ner. The  oil  production  was  allowed  to  accumulate  until  the  retort 
temperature,  read  as  previously  indicated,  had  reached  269°  C. 
(516°  F.),  then  the  oil  receiver  was  changed.  Likewise  receivers 
were  changed  when  the  temperature  had  reached  285°  C.  (545°  F.), 
322°  C.  (612°  F.),  and  when  the  run  was  completed.  Thus  four  oil 
samples  were  obtained,  the  first  representing  oil  production  from 
start  of  distillation  to  269°  C.,  >the  second  oil  produced  while  the 
retort  temperature  increased  from  269°  to  285°  C.,  and  so  on. 

This  report  deals  with  only  one  such  test,  but  several  others 
have  been  made,  oil  samples  being  taken  at  different  temperatures 
and  the  retort  being  operated  under  different  conditions.  All  these 
data  are  being  compared  and  correlated.  Analyses  of  oils  made 
under  different  retorting  conditions  are  valuable  as  they  not  only 
permit  a  comparison  of  products  made  under  various  conditions, 
but  show  the  effect  of  any  single  condition  on  the  quality  of  the 
product. 

In  the  near  future  a  complete  report  will  be  issued  giving 
details  as  to  the  analyses  of  the  various  oils  produced  during  the 
first  series  of  ten  runs  in  the  Boulder  retort.  This  report  will  also 
attempt  to  indicate  the  specific  effect  of  different  retorting  condi- 
tions on  the  quality  of  the  oils  produced. 


CO-OPERATIVE  OIL-SHALE  LABORATORY  43 

LABORATORY  PROCEDURE  FOR  EXAMINING  SHALE 

OILS. 

The  method  used  in  examining  shale  oils  is  practically  that 
used  by  the  United  States  Bureau  of  Mines  in  examining  petroleum, 
and  consists  essentially  of  the  following  steps  i1 

1.  The  sample  as  received  is  heated  in  the  container  until  it 
is  fluid.     (Most  shale  oils  are  of  the  consistency  of  butter  at  tem- 
peratures ranging  from  60°    to  95°    F.)      The   container  is  then 
shaken  to  thoroughly,  mix  the  contents  and  a  small  sample  taken 
therefrom  for  determination  of  water  percentage. 

2.  If  the  water  determination  indicates  only  a  small  percent- 
age of  water,  the  sample  is  allowed  to  stand  in  a  tightly  stoppered 
container  in  a  warm  place  until  the  bulk  of  the  water  has  settled 
out,  then  a  600  cubic  centimeter  sample  is  carefully  drawn  off  the 
top  and  placed  in  a  copper  topping-still.     The  light  oil  and  water 
are  distilled  from  the  sample,  and  the  water  separated  from  the 
light  oil.     After  the  remaining  oil  in  the  topping-still  has  cooled, 
the  light  oil  is  added  to  it,  and  thoroughly  mixed.     If  the  topping 
is  carefully  done,  and  cold  water  used  in  the  condenser,  the  loss 
during  topping-distillation  will  not  amount  to  more  than  a  few 
tenths  of  one  per  cent. 

Many  shale  oils,  however,  contain  a  large  percentage  of  water 
which  will  not  separate  on  standing,  and  when  such  a  sample  is  to 
be  run,  it  is  necessary  to  dehydrate  the  oil  by  means  of  a  drying 
agent.  In  such  cases  the  oil  is  placed  in  a  strong  steel  container 
provided  with  a  tightly  fitting  plug  and  thermometer-well,  and 
five  grams  of  calcium  chloride  are  added  for  every  cubic  centimeter 
of  water  contained  in  the  sample.  The  plug  is  then  screwed  down 
tightly  and  the  container  heated  gradually  until  the  contents  have 
reached  a  temperature  of  200°  C.  The  container  is  now  shaken 
until  it  has  cooled  to  room  temperature,  when  the  contents  may  be 
removed.  This  method  serves  to  dry  thoroughly  oils  containing 
large  amounts  of  water. 

3.  Specific  gravity  of  the  clean  oil,  dried  by  either  of  the 
above  methods,  is  then  taken  at  15.56°   C.   (60°  F.).     Practically 
all  shale  oils  are  semi-solid  at  this  temperature,  and  it  is  therefore 
necessary  to  use  some  type  of  specific  gravity  bottle  adapted  for 
use  with  solid  oils  and  tars.     The  Barrett  type  of  specific  gravity 
bottle  has  been  found  satisfactory  for  this  purpose. 

4.  The  specific  gravity  of  the  oil  having  been  determined, 
it  is  necessary  to  calculate  the  weight  of  oil  corresponding  to  300 
cubic  centimeters.     This  amount  is  weighed  into  the  Bureau  of 
Mines  standard  Hempel  distilling  flask.    This  flask,  whose  dimen- 
sions have  been  accurately  fixed,   consists  of  a  spherical   glass 
bulb  of  500  cubic  centimeter  capacity,  with  a  10-inch  vertical  neck 
or  column,  and  with  a  delivery  tube  springing  from  the  neck  nine 

1  The  apparatus  and  methods  used  in  these  tests  with  minor  exceptions, 
have  been  developed  in  the  Pittsburgh  laboratory  of  the  Bureau  of  Mines, 
and  are  fully  described  in  Bulletin  209  of  the  Bureau  of  Mines,  "The  Analyti- 
cal Distillation  of  Petroleum"  by  E.  W.  Dean,  soon  to  be  issued. 


44  SHORT  PAPERS  PROM  THE 

inches  up  the  column  at  an  angle  of  15  degrees  from  horizontal. 
After  the  oil  has  been  poured  into  the  flask  (it  is  often  necessary 
to  heat  the  oil  to  a  point  of  fluidity  before  it  can  be  poured  into 
the  flask)  an  8-inch  column  of  iron  "jack  chain"  to  serve  as  a 
fractionating  column  is  placed  in  the  vertical  neck.  A  cork, 
through  which  a  thermometer  passes,  is  fitted  into  the  top  of  the 
vertical  neck  of  the  flask.  The  thermometer  is  so  placed  that  the 
top  of  the  mercury  bulb  is  on  a  level  with  the  bottom  of  the  open- 
ing of  the  delivery  tube.  The  delivery  tube  is  connected  to  the 
condenser  with  a  well-fitting  cork.  The  condenser  consists  of  a 
vertical  three-bulb  staggered  glass  tube,  of  standardized  dimen- 
sions, set  in  an  insulated  jacket,  which  at  the  start  of  the  distil- 
lation is  filled  with  water  and  shaved  ice. 

5.  In  setting  up  the  distilling  outfit  all  joints  are  luted  with 
a  paste  of  litharge  and  glycerine.    The  Bureau  of  Mines  usually 
employs  an  electric  resistance  heater,  controlled  by  a  variable 
resistance,  to  heat  the  flask.     Distillation  is  allowed  to  proceed 
at  the  rate  of  about  two  cubic  centimeters  a  minute,  fractions 
being  separated  at  every  even  25°  C.  interval.     The  temperature 
of  the  first  drop  over  is  noted.    The  distillation  is  continued  until 
the  vapor  temperature  reaches  275°  C.,  all  fractions  taken  during 
the  intervals  of  25  degrees  temperature  rise  being  kept  separate 
in  stoppered  glass  tubes. 

6.  The  flask  is  next  allowed  to  cool,  the  column  of  chain  is 
removed  and  two  cones  of  copper  gauze  are  inserted  in  its  place. 
These  cones  are  placed  about  one  inch  apart  in  the  middle  of  the 
neck.     The  thermometer  is  then  replaced,  the  flask  connected  to 
the  condenser  as  before,  and  the  delivery  end  of  the  condenser 
connected  to  a  vacuum  receiver.    Fractions  may  now  be  obtained 
under  vacuum  without  breaking  the  vacuum  to  change  receivers. 
To  prevent  paraffin  wax  solidifying  in  the  tube,  the  water  in  the 
condenser  jacket  is   slowly  heated  with   an   electric   immersion 
heater  until  it  is  nearly  at  the  boiling  point  when  distillation  is 
complete.     Vacuum  distillation  is  conducted  at  a  pressure  of  40 
millimeters  of  mercury,  and  at  the  same  rate  as  during  the  air 
distillation.     Cuts  are  made  at  a  vapor  temperature  of  200°  C., 
and  at  every  25  degrees  up  to  300°  C.,  when  the  distillation  is 
stopped.     The  residuum  in  the  flask  is  allowed  to  cool,  and  its 
specific  gravity  and  setting  point  are  determined. 

7.  Fractions  taken  at  atmospheric  pressure   are  examined 
separately;  volume  and  specific  gravity  of  each  fraction  at  15.56° 
C.  being  determined. 

8.  Either  the  percentage  of  unsaturation  of  each  fraction 
is  determined,  or  the  percentage  of  unsaturation  of  the  combined 
fractions  distilling  up  to  200°  C.  is  determined.    The  separate  or 
combined   fractions   distilling  from   200°   G.   up   to   275   C°.   are 
similarly  tested.     Percentage  of  unsaturation  is  the  percentage 
soluble  in  sulphuric  acid  of  98  per  cent  strength.     Briefly,  the 
method  of  determining  unsaturation  consists  of  carefully  mixing 
5  cubic  centimeters  of  the  oil  with  10  cubic  centimeters  of  the 


CO-OPERATIVE  OIL-SHALE  LABORATORY  45 

acid,  in  a  small  bottle  with  graduated  neck,  keeping  the  bottle 
well  cooled  while  mixing  the  contents.  The  bottle  is  then  placed 
in  a  centrifuge  and  centrifuged  until  a  complete  separation  of  the 
oil  not  acted  on  by  the  acid  has  been  effected.1 

While  it  is  realized  that  this  method  does  not  accurately 
determine  the  absolute  percentage  of  unsaturated  hydrocarbons 
in  the  shale  oil  fractions,  nevertheless  close  checks  and  corre- 
sponding results  can  be  obtained.  The  method  is  quite  valuable 
for  purposes  of  comparison  because  it  indicates  at  least  the  com- 
parative order  of  refining  loss  that  the  oil  will  suffer.  Under 
the  conditions  of  the  test,  sulphuric  acid  probably  does  not  re- 
move all  the  unsaturated  hydrocarbons  of  the  olefin  series,  and 
probably  does  remove  some  of  the  higher  members  of  the  sat- 
urated hydrocarbon  series.  The  acid  also  removes  nitrogen  com- 
pounds from  the  oil.  The  acid,  however,  does  remove  all  the  hy- 
drocarbons that  are  most  objectionable  in  refined  products,  al- 
though commercial  refining  losses  can  be  expected  to  be  consid- 
erably lower  than  the  unsaturated  percentages  indicated  in  the 
tables. 

9.  The  fractions  taken  under  reduced  pressure  are  also  ex- 
amined separately.    Volume  and  specific  gravity  at  15.56°  C.  are 
determined,  using  the  specific  gravity  bottle  for  those  fractions 
that  are  solid  at  that  temperature.     A  Westphal  specific  gravity 
balance  can  be  used  for  all  fractions  that  are  entirely  fluid  at  the 
above  temperature. 

10.  Setting -points  of  the  vacuum  fractions  are  determined  by 
freezing  a  drop  of  the  oil  on  the  extreme  end  of  the  bulb  of  a  cooled 
thermometer,  inverting  the  thermometer  and  rotating  it  about  a 
vertical  axis  while  the  temperature  is  allowed  to  rise  at  the  rate 
of  1°  C.  per  minute.     In  most  cases  the  drop  of  oil  will  melt 
sharply  at  a  definite  temperature  and  flow  down  the  thermometer 
bulb.    This  temperature  is  the  setting  point,  and  gives  an  indica- 
tion of  the  paraffin  wax  content  of  the  fraction.     In  the  case  of 
some  residuums,  particularly  if  they  contain  much  asphalt,  the 
setting  point  cannot  be  determined  accurately  by  this  method. 

11.  The  viscosities  of  the  crude  oil,   and  of  the  fractions 
taken  off  under  vacuum,  are  taken  at  60°  C.  (140°  F.)  by  a  Say- 
bolt  Universal  Viscosimeter,  or  a  glass  pipette  viscosimeter  giving 
results  that  can  be  converted  into  Saybolt  readings. 

INTERPRETATION  OP  RESULTS  OF  DISTILLATION 

ANALYSES. 

The  following  is  quoted  from  a  paper  by  Dean2,  indicating 
how  the  results  of  distillations  are  interpreted  when  petroleum 
oils  are  examined. 


iSee  Dean,  E.  W.,  and  Hill,  H.  H.,  The  determination  of  unsaturated 
hydrocarbons  in  gasoline,  Bureau  of  Mines  Tech.  Paper  181,  1917,  for  details 
of  this  method. 

2  Dean,  E.  W.,  Properties  of  typicar  crude  oils  from  the  eastern,  producing 
fields  of  the  United  States,  Bureau  of  Mines,  Reports  of  Investigations,  Serial 
No.  2202,  January,  1921,  3  p. 


46  SHORT  PAPERS  FROM  THE 

"The  methods  employed  by  the  Bureau  of  Mines  for  the  dis- 
tillation analysis  of  crude  petroleum  have  not  been  developed 
with  the  idea  of  obtaining  figures  that  parallel  the  results  of 
actual  refinery  practice.  As  refinery  practice  has  never  been 
standardized,  it  has  been  necessary  to  select  a  fundamentally  re- 
producible basis  of  comparison,  rather  than  attempt  to  work  in 
terms  of  yields  and  properties  of  commercial  products. 

' '  The  chief  value  of  the  present  report  lies  in  the  fact  that  it 
permits  a  reasonably  adequate  comparison  of  different  crude 
oils  on  the  basis  of  fundamental,  physical  and  chemical  proper- 
ties. 

"It  is  believed  while  the  most  satisfactory  use  of  the  figures 
involves  a  comparison,  there  is  also  a  need  for  some  sort  of  'rough 
and  ready'  interpretation  in  terms  of  commercial  products.  There- 
fore, the  author  has  employed  the  following  classification  wrhich, 
even  if  it  has  no  other  justification,  is  convenient  because  it  per- 
mits discussion  in  terms  of  'given  names.' 

1.  "The  sum  of  all  fractions  distilling  at  atmospheric  pres- 
sure below  200°  C.  (392°F.)  is  reported  as  gasoline  and  naphtha. 

2.  "The  sum  of  all  fractions  distilling  at  atmospheric  pres- 
sure between  200°  C.  (392°  F.)  and  275°  C.  (527°  F.)  is  reported 
as  kerosene. 

3.  "The  sum  of  all  vacuum  distillation  fractions  having  Say- 
bolt  viscosities  (at  100°  F.)  of  less  than  50  seconds  is  reported  as 
gas  oil. 

4.  "The  sum  of  all  vacuum  distillation  fractions  having  Say- 
bolt  viscosities  (at  100°  F.)  between  the  inclusive  limits  of  50  and 
99  seconds  is  reported  as  light  lubricating  distillates. 

5.  "The  sum  of  all  vacuum  distillation  fractions  having  Say- 
bolt  viscosities  (at  100°  F.)  between  100  and  199  seconds  inclusive 
is  reported  as  medium  lubricating  distillate. 

6.  ' '  The  sum  of  all  vacuum  distillation  fractions  having  Say- 
bolt  viscosities  (at  100°  F.)  of  200  seconds  or  more,  is  reported  as 
viscous  lubricating  distillate." 

In  the  case  of  shale  oils,  the  above  interpretation  must  be 
applied  with  considerable  care.  In  the  first  place,  the  unsatura- 
tion  percentages  of  .the  crude  naphtha  and  kerosene  fractions  are 
usually  very  high,  indicating  a  high  refining  loss,  and  therefore 
the  percentages  of  finished  gasolines  and  kerosenes  will  be  con- 
siderably less  than  those  indicated  by  the  tables.  How  much  the 
refining  loss  will  be  is  as  yet  unknown. 

In  the  case  of  shale  oil  fractions  taken  off  under  vacuum,  the 
term  gas  oil  can  probably  be  applied  as  above,  but  since  little  is 
known  as  yet  of  the  properties  of  lubricating  oils  made  from 
shale  oil,  a  distillation  analysis  will  not  be  of  much  value  at  the 
present  time.  Later  on,  of  course,  when  shale  oils  are  actually 
refined  and  used,  results  of  the  examination  of  lubricating  frac- 
tions of  shale  oils  produced  by  laboratory  methods  can  be  com- 
pared with  the  oils  in  use,  and  a  reference  point  established.  At 


CO-OPERATIVE  OIL-SHALE  LABORATORY  47 

present  all  fractions  distilling  under  vacuum  above  225°  C.  are 
classified  as  crude  lubricating  distillates,  no  attempt  being  made 
to  classify  further.  About  the  only  conclusion  which  can  be 
reached  at  present  is  that  from  the  standpoint  of  viscosity ;  some 
lubricating  fractions  seem  suitable  for  making  satisfactory  lubri- 
cating oils.  The  possible  durability  of  such  lubricating  fractions 
in  actual  use  is  yet  to  be  determined,  and  durability,  after -all,  is 
the  property  that  deserves  major  emphasis  in  considering  a  lubri- 
cating oil. 

The  setting  points  of  the  higher  boiling  vacuum  fractions 
indicate  that  a  good  percentage  of  paraffin  wax  may  be  obtained 
from  the  shale  oils  examined.  Similar  setting  points  for  fractions 
of  the  Scotch  shale  oils,  shown  on  page  50,  are  of  interest  in  this 
connection. 

On  pages  48  to  50  inclusive  are  given  Tables  IX-A  to  IX-F 
showing  the  results  of  analytical  distillations  of  the  oils 
referred  to. 


48 


SHORT  PAPERS  FROM  THE 


TABLE  IX-A. 

ANALYTICAL  DISTILLATION  OP  SHALE  OIL  FROM 
COLORADO  OIL-SHALE. 

Sample  No.   B-003    (81). 

Oil-shale  from  DeBeque,  Colorado.  First  fraction  off  retort. 

Distilled   in  horizontal   rotary   retort.  Retort  temperature  up  to  269° 

Specific  gravity  oil,   0.937.  Baume  gravity,  19.4. 

Water  in  oil,  19.56  per  cent.     Setting  point  l    Viscosity  1 

Distillation,  Bureau  of  Mines  Hempel  Method. 
Air  distillation:  barometer,  645  mm.    First  drop,   52°   C.    (126°  F.). 


C. 


c 

si 

bD+J 

«<- 

II 

rtj  bfl 

^  3 

l,e 

.  3 

•    £ 

3  U 

Q,  Q) 

&H     Q 

ao 

00  £ 

-*j  .^ 

c  ^3 

O 

<u 

W 

JP 

«S  o> 

Pn 

ft 

H 

ga 

5 

P 

Up  to  50 

1         • 

50-  75 

0.34 

0.34 

75-100 

.27 

.61 

1 

i 

i 

100-125 

.95 

1.56 

125-150 

3.22 

4.78 

150-175 

3.87 

8.65 

0.817 

41 

4 

50.6 

175-200 

4.83 

13.48 

.839 

36 

9 

52.8 

200-225 

6.60 

20.08 

.858 

33 

2 

i 

225-250 

7.48 

27.56 

.875 

30. 

0 

55.8 

250-275 

10.54 

38.10 

.890 

27. 

3 

57.8 

Vacuum 

distilation 

at    40    i 

nm. 

Up  to  200 
200-225 

2.55 
7.75 

2.55 
10.30 

.908 

24 

2 

225-250 

8.26 

18.56 

.931 

20. 

4 

250-275 

7.92 

26.48 

.941 

18. 

8 

** 


Residuum:   specific  gravity   1.015;   setting  point  45' 
*Not    determined. 


C. 


Up  to  122 

122-167 

167-212 

212-257 

257-302 

302-347 

347-392 

392-437 

437-482 



482-527 

44 

i         Up  to  392 

392-437 

61 

17.5           437-482 

106 

27.0           482-527 

TABLE  IX-B. 

ANALYTICAL^  DISTILLATION  OF  SHALE  OIL  FROM 
COLORADO  OIL-SHALE. 

Sample  No.  B-002    (82). 

Oil-shale  from  DeBeque,  Colorado.  Second  fraction  off  retort. 

Distilled  in  horizontal  rotary  retort.  Retort  temperature  269°-285°  ( 

Specific   gravity   oil,   0.984.  Baume  gravity,   12.3. 

Water  in  oil,  4.75  per  cent.     Setting  point,  10°   C.  Viscosity,  :. 

Distillation,  Bureau  of  Mines  Hempel  Method. 
Air   distillation:    barometer   642   mm.    First   drop,    46°    C.    (114°    F.) 


0> 

Up  to  50 

t-i 
tr. 

Sum 
per  cen 

t» 

be!              Is 

£               g  a           £« 
P 

tabc            ea  hi 

C    Q)                         p|  tD 

M                   E-t 

Up  to  122 

50-  75 

0.51 

0.51 

J 

122-167 

75-100 

f       0.768 

52.3 

46.0          

167-212 

100-125 

l'.23 

1.74 

j 

212-257 

125-150 

3.90 

5.64 

J 

257-302 

150-175 

3.79 

9.43 

.803    . 

44.4 

49.6 

302-347 

175-200 

5.07 

14.50 

.825 

39.7 

52.6 

347-392 

200-225 

5.84 

20.34 

.843 

36.1 

i 

..    .           392-437 

225-250 

7.79 

28.13 

.866 

31.7 

54.6          '.'....'. 

437-482 

250-275 

9.44 

37.57 

.884 

28.4 

59.0 

482-527 

Vacuum    d: 

istillatioi 

i   at    40 

mm. 

Up  to  200 
200-225 

2.67 
7.90 

2.67 
10.57 

}         .906 

24.5 

43 

Up  to  392 
392-437 

225-250 

8.26 

18.83 

.929 

20.7 

58 

17           437-482 

250-275 

i 

Residuum: 

specific 

gravity 

1.173;  setting  point 

i^ 

'Not   determined. 


CO-OPERATIVE  OIL-SHALE  LABORATORY 


49 


TABLE  IX-C. 

ANALYTICAL  DISTILLATION  OP  SHALE  OIL  FROM 
COLORADO  OIL-SHALE. 

Sample  No.  B-004    (83). 

Oil-shale  from   DeBeque,   Colorado.  Third  fraction  from  retort. 

Distilled   in   horizontal   rotary   retort.  Retort   temperature   285°— 322°    C. 

Specific  gravity  oil,   0.918.  Baume  gravity,  22.5. 

Water  in  oil,  2.93  per  cent.     Setting-  point,  19°  C.        Viscosity  at  60°   C.,  56.' 

Distillation,  Bureau  of  Mines  Hemp  el  Method. 
Air  distillation:   barometer   640   mm.    First  drop  48°   C.     (118°   F.) 


Sbo 

3 

3  ° 

.  3 

hri  ' 

3 

p 

1 

<*£ 

P, 

VI 

s 

} 

H 

Up  to  50 

tr. 

tr.    ' 

50-  75 

0.271 

0.27 

75-100 

.542 

.81 

0.772 

51 

A 

100-125 

1.35 

2.16 

125-150 

3.39 

5.55  . 

150-175  | 

175-200  j 

8.12 

13.67 

.823 

40 

.1 

200-225 

4.57 

18.24 

.854 

33 

.9 

225-250 

6.17 

24.41 

.872 

30.6 

250-275 

6.85 

31.26 

.893 

26.8 

Vacuum   distillation 

at   40   mm. 

Up  to  200 
200-225 

2.58 
6,78 

2.58  1 
9.36 

.914 

23. 

2 

225-250 

7.88 

17.24 

.923 

21.7 

250-275 

8.27 

25.51 

.944 

18 

.3 

Residuum: 

specific 

gravity    1.004; 

setting 

very  asphaltic. 
Viscosity  at  100 


a  c 

S-.  HJ 

3  O 


49.0 


59.0 


point    not 


Up  to  122 
122-167 
167-212 
212-257 

257-302 
302-347 
347-392 
392-437 
437-482 

43 

S9          17.0 
98          26.5 
determined, 

482-527 

Up  to  392 
392-437 
437-482 
482-527 
residuum 

F.,  97. 


TABLE  IX-D. 

ANALYTICAL  DISTILLATION  OP  SHALE  OIL  PROM 
COLORADO  OILuSHALE. 

Sample  No.  B-001   (84). 

Oil-shale  from  DeBeque,   Colorado.  Fourth  cut  from  retort. 

Distilled  in  horizontal  rotary  retort.  Retort  temperature  599°  C. 

Specific  gravity  oil,   0.901.  Baume  gravity,  25.4. 

Water  in  oil,  2.59  per  cent.     Setting-  point  1.  Viscosity  at  60°   C.,   65. 

Distillation,  Bureau  of  Mines  Hempel  Method. 
Air   distillation:    barometer   645   mm.    First  drop    41°    C.     (106°    F.) 


|S 

<D 

£S 

3  « 

P. 

m 

to*                30 
f  V                Sfe 

Q            gp, 

EH 

P 

Up  to  50 

50-  75 

tr. 
0.33 

tr. 
0.33 

75-100 

.60 

.93 

0.773 

51.1 

50 

.6 

100-125 

2.13 

3.06 

125-150 

2.77 

5.83 

150-175 

4.00 

9.83  ' 

.809 

43.1 

53 

.2 

175-200 

4.40 

14.23 

.835 

37.7 

53 

.8 

200-225 

4.60 

18.83 

.856 

33.6 

59 

.2 

225-250 

4.83 

23.66 

.879 

29.3 

64 

.4 

250-275 

6.10 

29.76 

.900 

25.6 

67 

.6 

Vacuum  distillation 

at  40  mm. 

Up  to  200 
200-225 

2.21 
6.67 

2.21 
8.78 

.925 

21.4 

... 

225-250 

5.83 

14.61 

.941 

18.8 

250-275 

8.72 

23.33 

.966 

14.9 

... 

Residuum:  Specific  gravity 
1  Not  determined. 


Up  to  122 
122-167 
167-212 
212-257 
257-302 
302-347 
347-392 
392-437 
437-482 
482-527 

47 

65 
117 

Up  to  392 
392-437 
17           437-482 
30           482-527 

setting  point 


50 


SHORT  PAPERS  FROM  THE 


TABLE  IX-E. 

ANALYTICAL  DISTILLATION  OF  SHALE  OIL  FROM 
SCOTLAND2. 

Sample  No.  0-011. 

Oil-shale  from  Scotland.  Water  in  oil,  0.13  per  cent.     Setting  point  28C  C. 

Retorted  in  Pumpherston  commercial  retorts.  Baume  gravity,   29.6, 

Specific  gravity  oil,  0.877.  Viscosity  at  60°  C.,  44. 

Distillation,  Bureau  of  Mines  Hempel  Method. 
Air   distillation:   barometer   644   mm.    First  drop  49°    C.    (120°    F.) 

flT  ^  *^  <D 

Z,  o  ^  c  «-, 

3 


9 


Up  to  122 

122-167 
167-212 
212-257 
257-302 
302-347 
347-392 
392-437 
437-482 
482-527 

Up  to  392 
392-437 
437-482 
482-527 
527-572 


2  Does  not  include  scrubber  naphtha  which  amounts  to  10%  of  crude. 


1d 

li 

II 

.  3 

• 
W^j 
iip 

rtC 

!H    0> 

3  0 

fo 

ao 

c>  9? 

02  t-> 

ao 

£« 

•£J  t- 

MW 

C   0) 

c+  'O 

o 

V 

W 

ft 

$  * 

*4J 

4J  ^ 

5 

P-i 

a 

M 

•5 

^>   rt 

£ 

P 

0) 

99 

Up  to  50 
50-  75 

tr. 
0.13 

1 
0.13  1 

1 

75-100 

.32 

.45 

0.760 

54.2 

100-125 

.99 

1.44 

> 

•   28.0 

125-150 

1.66 

3.10  J 

f 

150-175 

3.00 

6.10 

.785 

48.3 

175-200 

6.12 

12.22 

.807 

43.5  J 

200-225 

8.10 

20.32 

.826 

39.5  } 

225-250 

6.65 

26.97 

.842 

36.3  [ 

34.0 

250-275 

8.47 

35.44 

.857 

33.4 

Vacuum   distillation  at   40   mm. 

Up  to  200 

9.32 

9.32 

.872 

30.6 

38 

200-225 

5.27 

14.59 

.881 

28.9 

40 

225-250 

7.16 

21.75 

.892 

27.0 

46 

24*.*5 

250-275 

6.13 

27.88 

.902 

25.2 

52 

29 

275-300 

6.07 

33.95 

.911 

23.7 

60 

34 

Residuum: 

specific 

gravity 

0.957    (16.3° 

Be.); 

setting 

point 

41°    C. 

TABLE  IX-F. 

ANALYTICAL  DISTILLATION  OF  CRUDE  OIL  FROM 
PENNSYLVANIA. 


Pennsylvania  crude  oil. 
Specific  gravity  oil,   0.812. 
Water  in  oil,  trace. 


Sample   No.   0-009. 


Baume  gravity,   42.4. 
Viscosity  at  60°   C.,   39. 


Distillation,  Bureau  of  Mines  Hempel  Method. 
Air  distillation:   barometer  644   mm.    First  drop   26°    C.    (79°   F.) 


II 


IP 


Up  to  50 
50-  75 

0.895 
1.612 

0.895  ) 
2.507J 

0.674 

77.7 

75-100 

4.08 

6.59 

.712 

66.6 

100-125 

8.29 

14.88 

.733 

61.0 

125-150 

5.46 

20.34 

.752 

56.2 

150-175 

6.77 

26.11 

.763 

53.5 

175-200 

5.82 

31.93 

.778 

50.0 

200-225 

6.95 

38.88 

.789 

47.4 

225-250 

6.42 

45.30 

.800 

45.0 

250-275 

7.46 

52.76 

.812 

42.4 

Vacuum 

distillation 

at   40   mm. 

Up  to  200 

3.33 

3.33 

.826 

39.5 

200-225 

7.75 

11.08 

.832 

38.3 

225-250 

6.02 

17.10 

.841 

36.5 

250-275 

5.37 

22.47 

.848 

35.1 

275-300 

5.16 

27.63 

.859 

33.0 

4.4 


3.6 


Residuum:   specific  gravity  0.882   (28.7°  Be.);  setting 


39 
40 
45 
51 
67 
point 


15.5 

22.5 

30.0 

18°    C. 


UP  to  122 
122-167 
167-212 
212-257 
257-302 
302-347 
347-392 
392-437 
437-482 
482-527 

Up  to  392 
392-437 
437-482 
482-527 
527-572 


CO-OPERATIVE  OIL-SHALE  LABORATORY  51 

COMPARISON  OP  ANALYSES  OF  SHALE  OILS. 

The  prime  purpose  of  this  paper  is  to  show  by  a  presentation 
of  experimental  data-  that  the  nature  of  the  oils  produced  from  the 
same  shales  at  different  temperatures  during  the  same  run  changes 
to  a  certain  extent,  but  that  the  change  is  so  small  that  it  is  of 
little  commercial  importance.  While  this  conclusion  can  be  drawn 
from  the  four  analyses  presented  in  this  paper,  it  is  emphasized  that 
the  conclusion  has  not  been  reached  as  a  result  of  these  four  an- 
alyses alone.  In  fact  some  fifty  samples  of  oil  produced  at  various 
temperatures  have  been  examined,  and  in  no  case  has  a  striking 
difference  been  found  in  the  oils  produced  at  different  stages  during 
the  same  retorting  test.  However,  striking  differences  have  been 
observed  between  oils  produced  in  different  runs  when  some  definite 
retorting  condition,  such  as  rate  of  rise  of  temperature,  has  been 
varied. 

Tables  IV-A  to  IX-F  contain  the  records  of  analytical  distilla- 
tions of  the  four  samples  of  oil  referred  to.  In  addition  they  give 
the  distillation  of  a  sample  of  commercial  Scotch  shale  oil  produced 
from  Scotch  shale  in  Scotland.  Also  there  is  presented  the  dis- 
tillation analysis  of  a  sample  of  high  grade  Pennsylvania  crude  oil. 
These  last  two  analyses  are  inserted  to  show  the  difference  between 
shale  oil  and  petroleum,  as  indicated  by  distillations,  and  between 
shale  oil  produced  in  Scotland  by  commercial  processes  and  the  oil 
produced  from  Colorado  oil-shale  in  the  Boulder  laboratory. 

It  is  important  to  note  that  the  operations  at  Boulder  are  of 
an  experimental  nature.  Often,  in  experimental  work,  negative 
results  are  as  valuable  as  positive,  since  negative  results  indicate 
what  not  to  do,  or  show  that  the  experiments  are  going  in  the  wrong 
direction.  The  oils  herein  reported,  therefore,  may  not  be  the  best 
oils  that  can  be  made  from  the  shale.  As  a  matter  of  fact,  better 
oils  are  constantly  being  produced  as  better  conditions  are  being 
determined  and  applied.  At  the  Intermountain  Experiment  Sta 
tion  of  the  Bureau  of  Mines,  Salt  Lake  City,  oils  have  already  been 
produced  by  laboratory  methods  from  Scotch  shale  that  equal  in 
every  respect  the  shale  oils  produced  in  commercial  operations  in 
Scotland.  So  far,  however,  it  has  not  been  possible  to  produce 
equally  satisfactory  oils  from  American  shales.  A  careful  exam- 
ination of  American  oil-shales  by  chemical  and  microscopic  means 
has  indicated  that  it  will  be  a  difficult  matter  to  produce  oils  from 
American  oil-shales  that  are  of  as  good  quality  as  Scotch  shale  oils,* 
because  of  the  differences  in  nature  and  origin  of  the  different 
shales.  Products  from  shales  from  different  parts1  of  the  United 
States,  and  even  from  different  parts  of  the  Green  River  forma- 
tion, show  a  marked  difference  although  the  shales  were  treated 
under  identical  conditions. 


52  SHORT  PAPERS  FROM  THE 


THERMAL  CALCULATIONS  ON  THE  RETORTING  OF 
OIL-SHALES. 

INTRODUCTION. 

Engineers  designing,  or  making  calculations  of  capacities  of 
oil-shale  retorting  equipment,  will  find  it  essential  to  determine  the 
amount  of  heat  necessary  to  retort  a  unit  weight  of  a  given  shale. 
Also,  it  will  often  be  desirable  to  know  how  much  of  that  heat  may 
be  supplied  by  the  shale  gas  and  spent  shale,  either  separately  or 
in  combination,  or  by  fresh  shale. 

Using  data  already  available,  or  presented  in  other  parts  of 
this  bulletin1,  this  paper  presents  calculations  approximately  indi- 
cating the  following : 

A.  The  theoretical  amount  of  heat  necessary  to  retort  an  oil- 
shale  at  various  temperatures. 

B.  The  total  amount  of  heat  necessary  to  retort  an  oil-shale 
at  various  furnace  efficiencies. 

C.  The  furnace  efficiencies  necessary  if  retorting  is  to  be  car- 
ried on  with  the  shale  gas,  or  shale  gas  and  spent  shale,  without  the 
introduction  of  other  fuel. 

METHOD  OF  MAKING  CALCULATION  OF  HEAT 
REQUIRED  FOR  RETORTING. 

In  order  to  obtain  a  set  of  figures-  which  might  serve  as  a  basis 
for  estimating  the  value  and  suitability  for  retorting  of  shales  of 
nearly  any  composition  likely  to  be  encountered,  the  following  pro- 
cedure was  used : 

The  composition  by  weight  (of  residue,  oil,  water  and  gas)  of 
four  ideal  shales  calculated  to  represent  probable  average  occur- 
rences in  the  Colorado-Utah  district  was  estimated.  These  ideal 
types  of  shales  produced  oil  at  rates  ranging  from  25  to  100  gallons 
of  oil  per  ton,  and  probably  cover  nearly  all  workable  oil-shales  in 
this  district.  The  composition  of  these  ideal  shales  is  given  in 
Table  X. 

Having  thus  established  the  weights  of  each  component  of  a 
set  of  shales  having  definite  assays  of  oil,  water  and  gas  yield,  the 
'heat  required  for  retorting  was  approximated  as  follows : 

1.     Certain  assumptions  were  made. 

(a)  A  maximum  temperature  of  retorting  was  as- 
signed. 

Cb)  The  specific  heat  of  the  shale  was  assumed  not 
to  vary  up  to  925°  C. 

(c)  A  temperature  was  assigned  as  that  of  the  begin- 
ning of  the  distillation. 

1  Most  of  the  factors  necessary  in  making  the  calculations  that  follow 
have  been  given  previously  in  publications  of  the  authors  or  in  this  bulletin, 
and  are  summarized  on  page  62. 


CO-OPERATIVE  OIL-SHALE  LABORATORY  53 

(d)  The  specific  heat  of  the  spent  shale  at  compara- 
tively high  temperature  is  assumed  to  be  the  same  as  that 
determined  at  a  lower  temperature. 

(e)  The  specific  heat  of  the  oil  vapor  is  assumed  to 
be  very  nearly  that  estimated  for  the  oil  at  lower  tempera- 
ture. 

(f)  The  .latent   heat   of  vaporization   of   the   oil   is 
assumed  to  be  nearly  that  of  its  lighter  constituents. 

(g)  The    average   specific   heat    of    the   permanent 
gases  formed  is  assumed -to  be  0.35. 

2.  Certain  errors,   at  present  partly  unavoidable,   are   neg- 
lected. 

(a>)  Those  errors  involved  in  the  assumption  regard- 
ing specific  heats,  above. 

(~b)  Errors  involved  in  considering  that  no  vapors 
of  either  water  or  oil,  or  gases,  are  given  off  below  the 
temperature  assigned  as  that  of  the  beginning  of  distilla- 
tion. 

(c)  Errors  involved  in  considering  that  all  vapors 
originate  at  the  temperature  of  the  beginning  of  distilla- 
tion and  are  carried  to  the  highest  temperature  of  dis- 
tillation before  discharge  from  the  retort. 

(d)  Errors  involved  in  lack  of  quantitative  informa- 
tion concerning  the  heat  of  decomposition  or  reaction  of 
the  shale  kerogen,  either  positive  or  negative.     The  heat 
of  reaction,  however,  is  believed  to  be  quite  small. 

Notwithstanding  the  assumptions  made,  and  the  errors  known 
to  be  introduced,  the  results  of  the  calculations  agree  well  with 
experimental  facts  as  is  shown  below. 

3.  The  various  factors  entering  into  the  heat  calculation  were 
assembled,  and  the  following  formula  obtained  for  calculating  the 
amount  of  heat  required  to  retort  a  unit  of  oil-shale  by  dry  dis- 
tillation, at  100  per  cent  heating  efficiency.     The  formula  can  be 
applied  from  the  results  of  an  assay  on  oil-shale  in  which  oil  and 
water  yields  and  weight  of  spent  shale  have  been  determined,  and 
weight  of  gas  evolved  arrived  at  by  difference.    Theoretical  amount 
of  heat,  in  small  calories1,  required  to  retort  oil-shale  by  dry  dis- 
tillation at  100  per  cent  efficiency  = 

454  \    S  [  (T,  —  T0)  C']  +  0  [r'  -f  (T2  —  TJ  C"]  + 
W  [r' '  +  (To  —  Tt)  C" ']  +  G  [  (T2  —  T,)  C' '  "]  + 
R  [  (T2  —  TJ  C"    "]  }' 
in  which : 

454  =  factor  for  converting  pounds  into  grams.  •  (If 
the  weights  used  are  expressed  as  grams  this  figure  is 
eliminated.) 

S  =  weight  in  pounds  of  shale  considered. 

*If  it  is  desired  to  convert  this  value  into  B.T.U.'s,  divide  the  result 
expressed  in  calories  by  252. 


54  SHORT  PAPERS  PROM  THE 

T0  =  temperature  of  shale  at  start  of  retorting 
(usually  atmospheric  temperature)  in  degrees  C. 

T!  =  temperature  in  degrees  C.  at  which  oil  is  first 
produced. 

T2  =  temperature  in  degrees  C.  at  end  of  distillation. 

C'  =  average  specific  heat  of  fresh  shale,  between  T0 
and  TI.  (Here  taken  as  0.265). 

C' '  =  average  specific  heat  of  oil  vapors  produced, 
between  Tx  and  T2.  (Here  taken  as  0.6.) 

C' "  =  average  specific  heat  of  steam  produced,  be- 
tween Tj.  and  T2.  (Here  taken  as  0.47.) 

C"  '  =  average  specific  heat  of  gas  produced,  be- 
tween T±  and  T2.  (Here  taken  as  0.35.) 

C"  " '  =  average  specific  heat  of  spent  shale  pro- 
duced, between  Tx  and  T2.  (Here  taken  as  0.225.) 

r'  =  latent  heat  of  vaporization  of  oil  produced. 
(Here  taken  as  100.) 

r' '  =  latent  heat  of  vaporization  of  water  produced. 
(540  calories  per  gram.) 

0  =  weight  of  oil  produced  in  pounds. 

W  =  weight  of  water  produced  in  pounds. 

G  =  weight  of  gas  produced  in  pounds. 

R  =  weight  of  spent  shale  (shale  residue)  in  pounds. 

The  following  calculation  is  shown  as  an  example,  in  which 
values  for  shale  No.  3,  Table  X,  are  used.  (For  a  summarized 
result  on  all  the  ideal  shales  considered,  see  Table  XIV.) 

The  shale  yielded  at  the  rate  of  375  pounds  of  oil,  41.7  pounds 
of  water,  1,383  pounds  of  spent  shale,  and  200  pounds  of  gas,  de- 
termined by  difference,  all  per  ton  of  shale.  The  unit  considered 
here  is  one  ton. 

Substituting  in  the  formula  shown: 

454  |  2000  [  (205  --  15)  0.265]  +  375  [100  +  (482  - 

205)    0.6]    +  41.7    [540  +    (482  -  -  205)    0.47]    +   200 

[   (482  —  205)  0.35]   +'1383   [   (482  --  205)   0.225]      j. 

=  149,272,000  calories  or  593,000  B.T.U. 

In  other  words,  the  dry  distillation  of  one  ton  of  the  shale 
under  consideration,  to  482°  C.  (900°  F.),  and  recovering  the  quan- 
tity of  products  above  set  forth,  would  require  149,272,000  calories, 
or  593,000  B.T.U.  of  heat,  if  the  retort  were  100  per  cent  thermally 
efficient.  Of  course  100  per  cent  efficiency  is  never  obtained,  and 
therefore  the  above  figure  must,  in  practice,  be  multiplied  by  a 
factor  based  on  the  efficiency  of  whatever  retort  is  used. 

I 


CO-OPERATIVE  OIL-SHALE  LABORATORY  55 

COMPARISON  OF  CALCULATED  AND  EXPERIMENTALLY 
DETERMINED  HEAT  REQUIREMENTS. 

It  is  possible  to  apply  the  formula  given  to  an  experiment  in 
which  the  actual  amount  of  heat  used  in  distilling  an  oil-shale  was 
determined.  Mr.  Arthur  J.  Franks,  of  Golden,  Colorado,  working 
entirely  independently  of  the  authors,  and  without  knowledge  of 
the  theoretical  work  being  undertaken  by  the  latter,  has,  by  means 
of  electrical  measurements,  roughly  determined  the  amount  of  heat 
necessary  to  distil  one  ton  of  oil-shale.  With  his  permission  his 
experimental  results  and  comments  have  been  included: 
Retorting  data: 

Weight  of  shale  distilled,  10  pounds. 
Average  temperature  inside  retort  wall,  535°  C. 
Time  of  retorting,  2  hours  (7200  seconds). 
Estimated  thermal  efficiency  of  retort,  75  to  85  per 
cent. 
Heat  measurements: 

Heat,  electrical. 

Average  voltage  during  test,  20. 
Average  amperage  during  test,  30. 
Total  watt  seconds  (20  X  30  X  7200)  =  4,320,000. 
One  watt  second  =  0.2389  small  calories. 

4,320,000  X  0.2389  =  1,033,000  calories  for  10  pounds 
of  shale,  or  206,600,000  gram  calories  per  2,000  pounds,  or 
820,000  B.T.U.  per  ton  of  shale. 
Products  obtained  per  ton  of  shale  retorted : 

Oil,  specific  gravity  assumed  0.900  at  15.56°  C.,  47.76 
gallons  or  357.9  pounds. 

Water,  specific  gravity  assumed  1.000,  7.14  gallons  or 
59.5  pounds. 

Gas,  assumed  specific  gravity  1.24  (air  =  1.0),  (gas 
contains  10.9  per  cent  C02),  3,260  cubic  feet  or  326 
pounds. 

Spent  shale,  1256.6  pounds. 

Substituting  the  above  weights  in  the  formula  given : 
454  \  2000  [  (205  —  15)  0.265]  +  537.9  [100  +  (535  - 
205)   0.6]    +  59.5    [540  +    (535  -  -  205)   0.47]    +   326 
[  (535  —  205)  0.35]  +  1256.6  [  (535  —  205)  0.225]     j. 
=  170,064,000  calories  or  677,000  B.  T.  U. 

It  will  be  recalled  that  Mr.  Frank's  experiment  indicated  that 
820,000  B.T.U. 's  were  required  to  retort  a  ton  of  the  shale  experi- 
mented with,  and  he  estimated  that  the  thermal  efficiency  of  his 
retort  was  from  75  to  85  per  cent.  Assuming  the  above  calculated 
value  represents  the  heat  required  at  100  per  cent  retort  efficiency, 
Mr.  Frank's  retort  was  82.56  per  cent  efficient. 

Although  this  close  agreement  does  not  constitute  a  general 
proof  of  the  reliability  of  the  formula,  or  even  an  absolute  proof 
for  this  specific  case,  it  would  seem  to  argue  strongly  in  favor  of 


56  SHORT  PAPERS  FROM  THE 

the  applicability  of  the  formula  for  at  least  approximations  until 
such  time  as  more  complete  data  allows  the  development  of  a  more 
exact  expression. 

It  is  regretted  that  similar  experimental  data  on  shales  of 
lower  and  higher  oil  yields  are  not  obtainable  to  furnish  bases  for 
other  confirmatory  calculations,  and  the  authors  will  greatly  appre- 
ciate any  authoritative  data  which  may  be  used  to  test  the  accuracy 
of  the  formula,  or  to  reduce  the  errors  and  assumptions  known  to 
be  involved  therein. 

CALCULATION  OF  HEAT  AVAILABLE  FROM  SHALE  GAS 
AND  SPENT  SHALE. 

From  considerations  developed  in  the  paper  on  "Fuel  Values 
of  Shale  and  Shale  Products, ' '  pages  13  to  21,  the  approximate  heat- 
ing value  of  each  of  the  ideal  shales  was  calculated  by  multiplying 
the  assay  yield  in  gallons  of  oil  per  ton  by  the  factor  106.6  to  arrive 
at  B.T.U.  value  per  pound,  and  by  2000  X  106.6  for  B.T.U.  value 
per  ton.  The  results  of  these  calculations  are  shown  in  Table  XI. 

From  further  considerations  developed  in  the  above  mentioned 
paper,  the  percentage  of  heat  found  in  each  product  was  estimated, 
and  also  the  heat  per  unit  of  each  product.  ( See  Table  IV,  page  18, 
and  discussion,  pages  15  and  16.)  Some  slight  adjustment  by  the 
method  of  trial  and  error  yielded  percentages  which,  upon  being 
applied,  gave  heat  values  to  units  that  checked  within  reasonable 
limits  those  determined  experimentally.  By  applying  these  per- 
centages to  the  original  heat  values,  the  results  presented  in  Tables 
XII  and  XIII  were  obtained.  These  figures  indicate  the  amount 
of  heat  available  in  the  products  of  retorting  one  ton  of  the  ideal 
shales  under  discussion. 

THERMAL  EFFICIENCIES  OF  RETORTS  NECESSARY  TO 

RETORT  OIL-SHALES  OF  DIFFERENT  RICHNESS. 

By  applying  the  formula  given  on  page  53  it  is  possible  to 
determine  the  amount  of  heat  required  to  retort  the  ideal  shales 
discussed.  Table  XIV  shows  the  results  of  such  determinations, 
considering  that  the  retorting  is  done  in  retorts  of  different  heating 
efficiencies. 

Now  having  obtained  figures  approximating  the  total  heat 
necessary  for  retorting  the  shales  (Table  XIV),  and  also  the  heat 
which  may  be  obtained  from  the  spent  shale  or  shale  gas,  or  both, 
(Table  XIII),  there  may  be  calculated  the  absolute  thermal  effi- 
ciency necessary  for  a  retort  which  is  to  handle  any  particular 
shale,  by  dry  distillation,  by  burning  either  the  shale  gas,  or  shale 
residue,  or  both,  with  no  additional  fuel.  Results  of  such  calcula- 
tions for  the  ideal  shales  considered  are  given  in  Table  XV. 

Both  the  fuel  necessary  to  retort  and  that  recoverable  from 
the  shale  depend,  of  course,  on  the  maximum  temperature  to  which 
the  shale  is  raised.  Therefore  results  of  two  sets  of  calculations, 
one  using  a  low  and  the  other  a  high  final  retorting  temperature, 
are  included  in  Tables  XIV  and  XV. 

All  calculations  are  slide-rule  estimations  and  therefore  correct 
to  the  third  significant  figure. 


CO-OPERATIVE  OIL-SHALE  LABORATORY 


57 


TABLE  X. 
COMPOSITION  BY  WEIGHT  OF  ONE  TON  OF  SHALE.1 


Shale 
No. 

Fresh 
shale 
Lbs. 

Oil2 
Lbs. 

Water 
Lbs. 

Gas3 
Lbs. 

Residue 
Lbs. 

Assay 

Oil 
Gals, 
per  ton 

Water 
Gals, 
per  ton 

Gas 
Cuft. 
per  ton 

1 

2000 

187.5 

41.70 

125 

1646.8 

25.0 

5.0 

2500 

2 

2000 

375.0 

41.70 

200 

1383.3 

50.0     . 

5.0 

4000 

3 

2000 

562.5 

.41.70 

250 

1146.8 

75.0 

5.0 

5000 

4 

2000 

750.0 

41.70 

250 

958.3. 

100.0 

5.0 

5000 

1Ideal  assumed  shales  (see  page  52). 
Specific  gravity  of  oil  assumed  as   0.900. 

3Specific  gravity  of  gas  assumed  as  0.656    (air  — 1);  1  cu.  ft.  gas  weighs 
0.05    Ibs. 


TABLE  XI. 

TOTAL  HEATING  VALUE  OF  OIL-SHALES  OF 
VARYING  RICHNESS. 


Shale 
No.1 

Richness  of  shale 
gals,  oil  per  ton 

Factor2 

B.  T.  U. 
per  Ib. 

B.  T.  U. 
per  ton. 

1 

25 

106.6 

2,665 

5,330,000 

2 

50 

106.6 

5,330 

10,660,000 

3 

75 

106.6 

7,995 

15,990,000 

4 

100 

106.6 

10,660  ' 

21,320,000 

'Numbers  refer  to  Table  X. 
2See  page  15. 


TABLE  XII. 

HEAT  VALUE  OF  PRODUCTS  ON  ONE  TON  OF  OIL-SHALES 
OF  DIFFERENT  RICHNESS. 


Residue 

Gas 

Oil 

Shale 
No.  ! 

Gals,  oil 
per  ton 

Total 
B.  T.  U. 

B.  T.  U. 
per  Ib. 

Total 
B.  T.  U. 

B.  T.  U. 
per  cu.  ft. 

Total 
B.  T.  U. 

B.  T.  U. 
per  Ib. 

1 

25 

995,000 

604 

818,000 

327 

3,465,000 

18,500 

2 

50 

1,990,000 

1,438 

1,636,000 

408 

6,930,000 

18,500 

3 

75 

2,399,000 

2,095 

2,559,000 

512 

10,395,000 

18,500 

4 

100 

2,342,000 

2,440 

3,410,000 

682 

13,860,000 

18,500 

lumbers  refer  to  Table  X. 


58 


SHORT  PAPERS  FROM  THE 


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CO-OPERATIVE  OIL-SHALE  LABORATORY 


59 


TABLE  XIV. 

HEAT  REQUIRED   TO  RETORT   OIL-SHALES   OF 
VARYING  RICHNESS. 


Shale 

No.  i 


Retort  efficiency  per  cent 
100  50  30  .   20 


Retort  efficiency  per  cent 
100  «50  30  20 


Heat  required  at  low  temperature, 

482°  C.  (900°  P.)  in 

1000  B.  T.  U.'s 


Heat  required  at  hi^rh  temperature, 

925°  C.  (1700°  F.)  in 

1000  B.  T.  U.'s 


1 

518 

1,036 

1,727 

2,590 

956 

1,912 

3,187 

4,780 

2 

593 

1,186 

1,976 

2,965 

1,091 

2,182 

3,637 

5,455 

3 

663 

1,326 

2,210 

3,315 

1,220 

2,440 

4,067 

6,100 

4 

725 

1,450 

2,416 

3,625 

1,350 

2,700 

4,500 

6,750 

'Numbers   refer   to   Table   X. 


60 


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CO-OPERATIVE  OIL-SHALE  LABORATORY  61 

CONVENIENT  FACTORS  FOR  USE  IN  OIL  SHALE 
CALCULATIONS. 


The  purpose  of  this  paper  is  to  present  factors  frequently 
used  in  making  oil-shale  calculations,  in  a  form  which  will  per- 
mit their  use  by  the  field  operator.  The  factors  presented  are  for 
purposes  of  arriving  at  close  approximations. 

All  the  figures  in  Table  XVI  are  taken  from  Mark's  "Me- 
chanical Engineer's  Handbook."  The  table  showing  effect  of 
altitude  on  atmospheric  pressure  (Table  XXV)  is  taken  from 
"Metallurgists  and  Chemists  Handbook,"  by  Liddell.  The  other 
tables  and  formulae  are  those  used  by  the  authors  in  the  course 
of  calculations  made  by  them.  They  are  in  general  merely  appli- 
cations of  well  known  principles  to  specific  cases.  The  physical 
data  for  shales  in  Table  XVII  are  those  determined  by  the 
authors,  most  of  them  having  been  previously  published.1  Con- 
siderable care  should  be  used  in  applying  them  as  they  were 
determined  only  for  shales  of  a  certain  average  richness  from  the 
Green  River  formation  in  Colorado.  It  is  believed,  however,  that 
they  may  have  rather  wide  application. 

TABLE  XVI. 
FREQUENTLY  USED  EQUIVALENTS. 

Length. 

1   centimeter  — 0.3937  inches.  1  inch  =  2. 54  centimeters,   (cm.) 

1  meter  =3. 281   feet.  1  foot  =  0.3048  meters,   (m.) 

1  meter  =1.0936  yards.  1  yard  =  0.9144  meters,    (m.) 

Areas. 

1   acre  =  43,560  square  feet. 
640  acres  =  1   square  mile. 

Volumes. 

1  cubic  inch  =  16. 39  cubic  centimeters,   (cc.) 

1  cubic  foot  =  1728  cubic  inches,      (cu.  in.) 

1  cubic   foot  =  28,352   cubic  centimeters,    (cc.) 

1   gallons  231    cubic    inches,    (cu.    in.) 

1  gallon  =  3785    cubic   centimeters,    (cc.) 

1   gallon  =  0.1357   cubic   feet.    (cu.  ft.) 

1  gallon  =  0.004951   cubic   yards,     (cu.   yds.) 

1000   cubic   centimeters  =  1.0    liter.    (1.) 

1  liter  =  0.03531   cubic  feet.    (cu.   ft.) 

1  cubic  meter  =  35. 3   cubic   feet.    (cu.   ft.) 

Mass. 

1  gram  =  weight  of  1  cubic  centimeter  of  pure  water  at  4°  C. 

28.35  grams  (gm.)=l  ounce,   (oz.) 

453.6   grams  —  1   pound    (Ib.)  —  16   ounces. 

1000    grams  —  1    kilogram    (kg.)  —  2.205    pounds. 

Miscellaneous. 

1  gallon  of  water   (specific  gravity  =  1.0)      —8.328  pounds  —  3780  grams. 

1   cubic   foot   of   water    (at   40°    C.)  =62.428    pounds. 

1  cubic  foot  of  water    (at  100°   C.)  =59.830   pounds. 

1   pound  of  water.  =0.12   gallons. 

1  pound   of   oil    (specific   gravity    0.9)  =0.1334   gallons. 

1  barrel  =  42  gallons  =350  pounds  of  liquid  of  specific 

gravity    l.OOO1. 

1  ton  of  oil    (specific   gravity   0.9)  =  5.72    barels. 

1   barrel    of   liquid  =  5.6154  cubic  feet. 

1  Gavin,  M.  J.,  and  Sharp,  L.  H.,  Some  physical  and  chemical  data  on 
Colorado  oil-shale,  Bureau  of  Mines,  Reports  of  Investigations  Serial  No. 
2152,  August,  1920,  8  pp. 

lrTo    calculate    pounds    per    barrel    of   any    other   liquid,    multiply    350    by 
specific  gravity  of  liquid. 


62 


SHORT  PAPERS  FROM  THE 


TABLE  XVII. 
SOME  CONSTANTS  FOR  SHALE  AND  SHALE  PRODUCTS. 


Fresh  shale    Spent  shale 


Shale  oil 


Specific    heat 


0.2652 


0.2253 


Calories  per  gram....  Assay  in  gal-  Approximately 
Ions  ner  ton       0.2319  x  heat 


0.5—0.6 
10,270 


X59.25 


value  of 

fresh  shale 

from  which  it 

was  derived. 


B.  T.  U.  per  pound 


Latent   heat   of 
vaporization 


Assay  in  gal-    Aonroximately 

Ions  per  ton        0.2319  x  heat 

x  106.6  value  of 

fresh  shale 
from  which  it 
was  derived. 


18,500 


100 


Shale  eras1    Steam 


0.354 


Varies  from 
300  to  600 

B.  T.  U.  per 

cu.  ft.  at 
0°C.,  760  mm. 


Water 

540 


0.47 


'Produced  from  shale  by  dry  destructive  distillation. 

2Colorado   oil-shale   yielding   42    gallons  of  oil   per   ton. 

aResidue   from   Colorado   oil-shale   yielding    42    gallons   of   oil   per   ton. 

•^Approximately. 


TABLE  XVIII. 
HEAT  EQUIVALENTS. 

The  calorie  (small  calorie  or  gram  calorie)  is  the  quantity  of  heat  re- 
quired to  raise  the  temperature  of  one  gram  of  pure  water  fromi  4°  to  5° 
Centigrade.  The  mean  calorie,  commonly  used  by  engineers,  and  in  this 
paper,  is  1/100  of  the  quantity  of  heat  required  to  raise  the  temperature  of 
1  gram  of  pure  water  from  0°  to  100°  Centigrade.  It  is  nearly  the  same  as 
the  amount  of  heat  required  to  raise  the  temperature  of  1  gram  of  pure 
water  from  17°  to  18°  Centigrade. 

The  large  Calorie  (kilogram  Calorie)  is  1000  times  the  small  calorie,  in 
whatever  form  the  small  calorie  may  be  expressed. 

The  British  Thermal  Unit  (B.  T.  U.  )  is  the  quantity  of  heat  required  to 
raise  the  temperature  of  1  pound  of  pure  water  one  degree  Fahrenheit,  at 
39.1°  F.,  the  temperature  of  the  maximum  density  of  water.  The  Mean 
British  Thermal  Unit  is  1/180  of  the  quantity  of  heat  required  to  raise  the 
temperature  of  one  pound  of  pure  water  from  32°  to  212°  Fahrenheit.  It  is 
the  term  commonly  used  in  American  engineering  practice. 

1    B.  T.  U.—  252    calories—  0.252    kilogram   Calories. 

1    kilogram    Calorie—  3.968    B.  T.  U.'s. 

To  change  calories  per  gram  to  B.  T.  U.  per  pound,  multiply  by  1.8   (9/5). 

To  change  B.  T.  U.  per  pound  to  calories  per  gram,  divide  by  1.8  (or 
multiply  by  5/9). 

TABLE  XIX. 
TEMPERATURES. 


Fahrenheit    scale    (F.):    Freezing   point    of    water—  32°;    boiling    point   of 
water=212°. 

Centigrade    scale    (C.):    Freezing    point    of    water—  0° 
water—  100°. 

Absolute    scale    (A.):    Freezing    point    of    water—  273 
water—  373V 

To  change  temperature  in 

To  change  temperature  in 

To  change  temperature  in 

To  change  temperature  in 

To  change  temperature  in 

To  change  temperature   in 


boiling    point    of 
boiling    point    of 


F.  to   °C.:    (F.  reading — 32)  X    5/9  =  °C. 
C.  to  °F.:   (C.  readingX9/5)+32  =  °F. 

A..  C.  reading+273  =  °A. 

C.:   A.   reading — 273=  °C. 

A.:  convert  to  °C.  then  apply  above. 

'F. :  convert  to  °C.  then  apply  above. 


>C.  to 
°A  to 
DF.  to 

°A.  to 


Absolute  temperatures  are   sometimes  expressed   in   Fahrenheit  units   in- 
stead of  Centigrade  units.    Add  459°   to  Fahrenheit  reading  for  this  purpose. 


CO-OPERATIVE  OIL-SHALE  LABORATORY  63 

TABLE  XX. 
WEIGHT  OF  SHALE. 

(For  approximations  only.) 


Specific 

gravity  of 
shale. 

Weight  per  cubic  foot 
Pounds.                   Tons. 

Weight  per  acre  per 
foot  of  thickness. 

1.5 

93.7 

.04685 

2040  tons 

1.6 

99.9 

.04999 

2176  tons 

1.7 

106.1 

.05305 

2310  tons 

1.8 

112.3 

.05615 

2445  tons 

1.9 

118.7 

.05935 

2583  tons 

2.0 

125.0 

.06250 

2721  tons 

2.1 

131.1 

.06555 

2858  tons 

2.2 

137.3 

.06865 

2990  tons 

2.3 

143.6 

.07180 

3124  tons 

2.4 

150.0 

.07500 

3265  tons 

2.5 

156.3 

.07815 

3405  tons 

Formula:    1    cubic    foot— 28,353    cubic    centimeters. 

(1)  Specific  gravity  X  28, 353  or   (specific  gravity  X  62.5)  =  pounds  per  cubic 
foot.  454 

(2)  Pounds    per   cubic   foot  — tons    per   cubic   foot. 

2000 

(3)  Tons    per    cubic    foot  X  43, 560  :=  tons    per    acre    per    foot    of    thickness. 
Weight  of  shale  in  place  is  much  greater  per  cubic  foot  than  when  mined. 
Weight  per  cubic  foot  mined  varies  from,  0.42  to  0.5  of  its  weight  in  place 

according-  to  the   size  to  which   it  is  crushed.    The  finer  the  shale  is  crushed 
the   greater   its   weight    per   cubic   foot. 

One    cubic    foot    in    place    when    mined    will    yield     1     to    1   ,    i.    e.,    2.38 
to   2.0   cubic  feet.  0.42        0.5 

TABLE  XXI.1 

PETROLEUM  OIL  TABLE  FOR  CONVERTING  SPECIFIC 
GRAVITY  TO  BAUME  DEGREES. 


Specific 
gravitv 
60°/60°F. 

Degrees 
Baume 
(Modulus  140) 

Pounds 
per 
gallon 

Gallons 
per 
pound 

0.600 

103.33 

4.993 

0.2003 

.610 

99.51 

5.076 

.1970 

.620 

95.81 

5.160 

.1938 

.630 

92  22 

5.243 

.1907 

.640 

88.75 

5.326 

.1877 

.650 

85.38 

5.410 

.1848 

.660 

82.12 

5.493 

.1820 

.670 

78.96 

5.577 

.1793 

.680 

75.88 

5.660 

.1767 

.690 

72.90 

5.743 

.1741 

.700 

70.00 

5.827 

.1716 

.710 

67.18 

5.910 

.1692 

-720 

64.44 

5.994 

.1668 

.730 

61.78 

6.077 

.1646 

.740 

59.19 

6.160 

.1623 

.750 

56.67 

6.244 

.1602 

.760 

54.21 

6.327 

.1580 

.770 

51.82 

6.410 

.1560 

.780 

49.49 

6.494 

.1540 

.790 

47.22 

6.577 

.1520 

.800 

45.00 

6.661 

.1501 

.810 

42.84 

6.744 

.1483 

.820 

40.73 

6.827 

.1465 

.830 

38.68 

6.911 

.1447 

.840 

36.67 

6.994 

.1430 

.850 

34.71 

7.078 

.1413 

.860 

32.79 

7.161 

.1396 

64 


SHORT  PAPERS  FROM  THE 


PETROLEUM  OIL  TABLE  FOR  CONVERTING  SPECIFIC 
GRAVITY  TO  BAUME  DEGREES— Continued. 


Specific 
gravity 
60°/60°  F. 

Degrees 
Baume 
(Modulus  140) 

Pounds 
per 

gallon 

Gallons 
per 

pound 

.870 

30.92 

7.244 

.1380 

.880 

29.09 

7.328 

.1365 

.890 

27.30 

7.411 

.1349 

.900 

25.56 

7.494 

.1334 

.910 

23.85 

7.578 

.1320 

.920 

22.17 

7.661 

.1305 

.930 

20.54 

7.745 

.1291 

.940 

18.94 

7.828 

.1278 

.950 

17.37 

7.911 

.1264 

.960 

15.83 

/           7.995 

.1251 

.970 

14.33 

8.078 

.1238 

.980 

12.86 

8.162 

.1225 

.990 

11.41 

8.245 

.1213 

xThis  and  the  following-  three  tables  are  taken  from  United  States 
Standard  tables  for  Petroleum  Oils,  Circular  57,  U.  S.  Bureau  Standards, 
1916,  64  pp. 

TABLE  XXII. 

PETROLEUM  OIL  TABLE  FOR  CONVERTING  BAUME 
DEGREES  TO  SPECIFIC  GRAVITY. 


Degrees  Specific 
Baume  gravity 
(Modulus  60°/60° 
140)      F. 

Pounds 
per 
gallon 

Gallons 
per 
pound 

Degrees  Specific 
Baume  gravity 
(Modulus  60°/60° 
140)     F. 

Pounds 
per 
gallon 

Gallons 
per 
pound 

10.0 

1.0000 

8.328 

0.1201 

55.0 

0.7568 

6.300 

0.1587 

11.0 

.9929  . 

8.269 

.1209 

56.0 

.7527 

6.266 

.1596 

12.0 

.9859 

8.211 

.1218 

57.0 

.7487 

6.233 

.1604 

13.0 

.9790 

8.153 

.1227 

58.0 

.7447 

6.199 

.1613 

14.0 

.9722 

8.096 

.1235 

59.0 

.7407 

6.166 

.1622 

JK.fl 

.^55 

8  r  '  1 

.1244 

60.0 

.7368 

6.134 

.1630 

16.0 

.9589 

7.986 

.1252 

61.0 

.7330 

6.102 

.1639 

17.0 

.9524 

7.031 

.1261 

62.0 

.7292 

6.070 

.1647 

18.0 

.9459 

7.877 

.1270 

63.0 

.7254 

6.038 

.1656 

19.0 

.9396 

7.825 

.1278 

64.0 

.7216 

6.007 

.1665 

20.0 

.9333 

7.772 

.1287 

65.0 

.7179 

5.976 

.1673 

21.0 

.9272 

7.721 

.1295 

66.0 

.7143 

5.946 

.1682 

0<>.0 

rpi  1 

7  <"?  ' 

.1304 

67.0 

.7107 

5.916 

.1690 

23.0 

!9150 

7.620 

.1313 

68.0 

.7071 

5.886 

.1699 

24.0 

.9091 

7.570 

.1321- 

69.0 

.7035 

5.856 

.1708 

25.0 

.9032 

7.522 

.1330 

70.0 

.7000 

5.827 

.1716 

26.0 

.8974 

7.47^ 

.1338 

71.0 

.6965 

5.798 

.1725 

27.0 

.8917 

7.425 

.1347 

72.0 

.6931 

5.769 

.1733 

28.0 

.8861 

7.378 

.1355 

73.0 

.6897 

5.741 

.1742 

?9  0 

.8805 

7.3°5> 

.1364 

74.0 

.6863 

5.712 

.1751 

30:0 

.8750 

7.286 

.1373 

75.0 

.6829 

5.685 

.1759 

31.0 

.8696 

7.241 

.1381 

76.0 

.6796 

5.657 

.1768 

32.0 

.8642 

7.196 

.1390 

77.0 

.6763 

5.629 

.1776 

33.0 

.8589 

7.152 

.1398 

78.0 

.6731 

5.602 

.1785 

^4.0 

.8537 

7.108 

.1407 

79.0 

.6699 

5.576 

.1793 

35.0 

.8485 

7.065 

.1415 

80.0 

.6667 

5.549 

.1802 

?fi  0 

.8434 

7.  '"?2 

.1424 

81.0 

.6635 

5.522 

.1811 

37.0 

.8383- 

6.980 

.1433 

82.0 

.6604 

5.497 

.1819 

38.0 

.8333 

6.939 

.1441 

83.0 

.6573 

5.471 

.1828 

39.0 

.8284 

6.898 

.1450 

84.0 

.6542 

5.445 

.1837 

40.0 

.8235 

6.857 

.1459 

85.0 

.6512 

5.420 

.1845 

41.0 

.8187 

6.817 

.1467 

86.0 

.6482 

5.395 

.1854 

42.0 

.8140 

6.777 

.1476 

87.0 

.6452 

5.370 

.1862 

43.0 

.8092 

6.738 

.1484 

88.0 

.6422 

5.345 

.1871 

44.0 

.8046 

6.699 

.1493 

89.0 

.6393 

5.320 

.1880 

45.0 

.8000 

6.661 

.1501 

90.0 

.6364 

5.296 

.1888 

46.0 

.7955 

6.62^ 

.1510 

91.0 

.6335 

5.272 

.1897 

47.Q 

7910 

P  58fi 

.1518 

92.0 

.6306 

5.248 

.1905 

48.0 

.7865 

6.548 

.1527 

93.0 

.6278 

5.225 

.1914 

49  0 

.7821 

6.511 

.1536 

94.0 

.6250 

5.201 

.1923 

50.0 

.7778 

6.476 

.1544 

95.0 

.6222 

5.178 

.1931 

51.0 

.7735 

6.440 

.1553 

96.0 

.6195 

5.155 

.1940 

52.0 

.7692 

8.404 

.1562 

97.0 

.6167 

5.132 

.1949 

53.0 

.7650   . 

6.369 

.1570 

98.0 

.6140 

5.110 

.1957 

54.0 

.7609 

6.334 

.1579 

99.0 

.6114 

5.088 

.1966 

55.0 

.7568 

6.300 

.1587 

100.0 

.6087 

5.066 

.1974 

CO-OPERATIVE  OIL-SHALE  LABORATORY 


65 


TABLE  XXIII.1 

TEMPERATURE    CORRECTIONS    TO    READINGS    OF    SPE- 
CIFIC   GRAVITY    HYDROMETERS    IN    AMERICAN 
PETROLEUM    OILS    AT    VARIOUS    TEM- 
PERATURES. 


(Standard  at  60°/60°  p.) 


OBSERVED  SPECIFIC 

GRAVITY 

Observed 
tempeiature 

0.650 

0.700 

0.750 

0.800 

0.850 

0.900 

0.950 

Subtract  from,  observed  specific  gravity 

30 

0.016 

0.015 

0.014 

0.012     0.011 

0.011 

0.011 

32 

.015 

.014 

.013 

.012 

.011 

.010 

.010 

34 

.014 

.013 

.012 

.011 

.010 

.010 

.010 

36 

.013 

.012 

.011 

.010 

.009 

.009 

.009 

38 

.012 

.011 

.010 

.009 

.008 

.008 

.008 

40 

.0105 

.0095 

.0090 

.0080 

.0075 

.0070 

.0070 

42 

.0095 

.0085 

.0("80 

.0070 

.0065 

.0065 

.0065 

44 

.0085 

.0075 

.0070 

.0065 

.0060 

.0060 

.0055 

46 

.0075 

.0065 

.0060 

.0055 

.0050 

.0050 

.0050 

48 

.0065 

.0060 

.0055 

.0050 

.0045 

.0045 

.0040 

50 

.0050 

.0050 

.0045 

.0040 

.0035 

.0035 

.0035 

52 

.0040 

.0040 

.0035 

.0030 

.0030 

.0030 

.0030 

54 

.0030 

.0030 

.0025 

.0025 

.0020 

.0020 

.0020 

56 

.0090 

0020 

.0020 

.0015 

.0015 

.0015 

.0015 

58 

.0010 

.0010 

.0010 

.0005 

.0005 

.0005 

.0005 

Add  to  observed  specific 

gravity 

60 

.0000 

.0000 

.0000 

.0000 

.0000 

.0000 

.0000 

62 

.0010 

.0010 

.0010 

.0005 

.0005 

.0005 

64 

.0020 

.0020 

.0015 

.0015 

.0015 

.0015 

66 

.0030 

.0030 

.0025 

.0025 

.0020 

.0020 

68 

.0040 

.0040 

.0035 

.0030 

.0030 

.0030 

70 

.0050 

.0050 

,0045 

.0040 

.0040 

.0035 

72 

.0060 

.0055 

.0050 

.0045 

.0045 

.0040 

74 

.0070 

.0065 

.0060 

.0055 

.0050 

.0050 

76 

.0080 

.0075 

.0070 

.0065 

.0060 

.0055 

78 

.0090 

.0085 

.0080 

.0070 

.0065 

.0065 

80 

.010 

.009 

.008 

.008 

.007 

.007 

82 

.011 

.010 

.009 

.008 

.008 

.007 

84 

.012 

.011 

.,010 

.009 

.009 

.008 

86 

.013 

.012 

.011 

.010 

.009 

.009 

88 

.014 

.013 

.012 

.011 

.010 

.010 

90 

.015 

.014 

.013 

.012 

.011 

.010 

92 

.016 

.015 

.013 

.012 

.011 

.011 

94 

.017 

.016 

.014 

.013 

.012 

.012 

96 

.018 

.016 

.015 

.014 

.013 

.013 

98 

.019 

.017 

.016 

.015 

.014 

.013 

100 

.020 

.018 

.017 

.015 

.014 

.014 

102 

.021 

.019 

.018 

.016 

.015 

.015 

104 

.022 

.020 

.018 

.017 

.016 

.015 

106 

.023 

.021 

.019 

.017 

.016 

.016 

108 

024 

.022 

.020 

.018 

.017 

.017 

110 

.025 

.023 

.021 

.019 

.018 

.017 

112 

.026 

.024 

.022 

.020 

.019 

.018 

114 

.027 

.025 

.022 

.020 

.019 

.019 

116 

028 

.026 

.023 

.021 

.020 

.019 

118 

.029 

.026 

.024 

022 

.021 

.020 

120 

.030 

.027 

.025 

.023 

.022 

.021 

llt  is  not  definitely  known  that  the  figures  in  this  table  can  be  applied 
to  shale  oils,  as  the  coefficients  of  expansion  of  shale  oils  are  not  known  at 
present.  Oils  produced  from  different  shales  or  under  different  conditions 
from  the  same  shale,  may  have  different  coefficients,  but  it  is  believed  that 
the  above  figures  will  apply  for  fairly  close  approximations  in  most  cases 
It  is  possible  that  new  tables  must  be  worked  out  for  shale  oils. 


66 


SHORT  PAPERS  FROM  THE 


TABLE  XXIV.1 

TEMPERATURE  CORRECTIONS  TO  READINGS  OF  BAUME 

HYDROMETERS  IN  AMERICAN  PETROLEUM  OILS 

AT  VARIOUS  TEMPERATURES. 


(Standard  at  60°  F. ;  modulus  140.) 


OBSERVED   DEGREES 

BAUME 

Observed 

20.0 

30.0 

40.0 

50.0 

60.0 

70.0            S 

0.0 

90.0 

temperature  ~~ 
deg.  F. 

Add 

to  observed  degrees 

Baume 

30 

1.7 

2.0 

2.4 

3.0 

3.7 

4.3 

5.0 

5.7 

32 

1.6 

1.9 

2.3 

2.8 

3.4 

4.0 

4.7 

5.3 

34 

1.5 

^.8 

2.1 

2.6 

3.1 

3.7 

4.3 

4.9 

36 

1.4 

1.6 

2.0 

2.4 

2.9 

3.4 

4.0 

4.6 

38 

1.3 

1.5 

1.8 

2.2 

2.6 

3.1 

3.6 

4.2 

40 

1.2 

1.4 

1.6 

2.0 

2.4 

2.8 

3.2 

3.8 

42 

1.1 

1.2 

1.5 

1.8 

2.2 

2.5 

2.9 

3.4 

44 

.9 

1.1 

1.3 

1.6 

2.0 

2.2 

2.6 

3.0 

46 

.8 

.9 

1.1 

1.4 

1.7 

1.9 

2.3 

2.7 

48        i  • 

.7 

.8 

.9 

1.2 

1.4 

1.6 

2.0 

2.3 

50 

.6 

.7 

.8 

1.0 

1.2 

1.4 

1.6 

1.9 

52 

.5 

.6 

7 

.8 

1.0 

1.1 

1.3 

1.5 

54 

.3 

A 

.5 

.6 

.8 

.9 

1.0 

1.1 

56.        , 

2 

.3 

.3 

.4 

.5 

.6 

.6 

.7 

58 

!i 

.1 

.1 

.2 

.3 

.3 

.3 

.4 

Subtract 

from  observed  degrees  Baume 

CO 

.0 

.0 

.0 

.0 

.0 

.0 

.0 

.0 

62: 

.1 

.1 

.1 

.2 

.2 

.3 

.3 

.4 

6.4 

.2 

.3 

.3 

.4 

.4 

.6 

.6 

.7 

66 

.3 

.4 

.5 

.6 

.7 

.8 

.9 

1.0 

68 

.5 

.6 

.6 

.7 

.9 

1.1 

1.3 

1.4 

70        j. 

.6 

.7 

.8 

.9 

1.1 

1.4 

1.6 

1.7 

72 

.7 

.8 

.9 

1.1 

1.3 

1.6 

1.9 

2.1 

74 

.8 

.9 

.1 

1.3 

1.6 

1.8 

2.2 

2.5 

76 

.9 

.1 

.3 

1.5 

1.8 

2.1 

2.5 

2.8 

is     :  ;      i 

1.0 

.2 

.4 

1.7 

2.0 

2.4 

2.8 

3.1 

80 

1.1 

.3 

.5 

1.8 

2.2 

2.6 

3.1 

3.5 

82 

1.2 

.4 

.7 

2.0 

2.5 

2.9 

3.4 

3.9 

84 

1.3 

.5 

1.8 

2.2 

2.7 

3.2 

3.7 

4.3 

86; 

1.4 

.7 

2.0 

2.4 

2.9 

3.4 

4.0 

4.6 

88      :     - 

1.6 

.8 

2.1 

2.6 

3.1 

3.7 

4.2 

4.9 

90 

1.7     • 

2.0 

2.3 

2.7 

3.3 

3.9 

4.5 

5.2 

92 

1.8 

2.1 

2.4 

2.9 

3.5 

4.2 

4.8 

5.6 

94 

1.9 

2.2 

2.6 

3.1 

3.8 

4.4 

5.1 

5.9 

96. 

2.0 

2.3 

2.7 

3.3 

4.0 

4.6 

5.4 

6.3 

98 

2.1 

2.4 

2.9 

3.4 

4.2 

4.9 

5.7 

6.6 

100 

2.2 

2.6 

3.0 

3.6 

4.4 

5.1 

6.0 

6.9 

102 

2.3 

2.7 

3.2 

3.8 

4.6 

5.4 

6.3 

7.2 

104 

2.4 

2.9 

3.3 

4.0 

4.8 

5.7 

6.6 

7.5 

106     • 

2.5 

3.0 

3.5 

4.2 

5.0 

5.9 

6.9 

7.9 

108 

2.7 

3.1 

3.6 

4.3 

5.2 

6.2 

7.2 

8.2 

110 

2.8 

3.2 

3.7 

4.4 

5.4 

6.4 

7.5 

8.5 

112 

2.9 

3.3 

3.9 

4.6 

5.6 

6.7 

7.7 

8.8 

114 

3.0 

3.4 

4.0 

4.7 

5.8 

6.9 

7.9 

9.1 

116 

3.1 

3.6 

4.1 

4.9 

6.0 

7.1 

8.2 

9.4 

118 

3.2 

3.7 

4.3 

5.1 

6.2 

7.3 

8.5 

9.8 

120 

3.3 

3.8 

4.4 

5.3 

6.4 

7.5 

8.8 

10.  1 

alt  is  not  definitely  known  that  the  figures  in  this  table  can  be  applied  to 
shale  oils,  as  the  coefficients  of  expansion  of  shale  oils  are  not  known  at^ 
present.  Oils  produced  from  different  shales  or  under  different  conditions 
from  the  same  shale  may  have  different  coefficients,  but  it  is  believed  that 
the  above  figures  will  apnly  for  fairly  close  approximations  in  most  cases. 
It  is  possible  that  new  tables  must  be  worked  out  for  shale  oils. 


CO-OPERATIVE  OIL-SHALE  LABORATORY 


67 


TABLE  XXV. 

RELATION  BETWEEN  ALTITUDE  AND  BAROMETRIC 

PRESSURE.1 


Altitude 
in  feet 

.Barometer         Atmospheric  pressure   Proportionate  atmos* 
in  inches                      in  Ibs.  per  sq  in.           pheric  density 

0.00 

30.0 

14.72 

1.00 

500.0 

29.5 

14.45 

0.98 

1,000.0 

28.9 

14.18 

0.96 

1,500.0 

28.4 

13.94 

0.94 

2,000.0 

27.9 

13.69 

0.93 

2,500.0 

27.4 

13.45 

0.91 

3,000.0 

26.9 

13.20 

0.89 

4,000.0 

26.0 

12.75 

0.86 

5,000.0 

25.1 

12.30 

0.83 

6,000.0 

24.2 

11.85 

0.80 

7,000.0 

23.3 

11.44 

0.77 

8,000.0 

22.5 

11.04 

0.75 

9.000.0 

21.7       . 

10.65 

0.73 

10,000.0 

20.9 

10.26 

0.70 

'Liddell,  D.  M.,  Metallurgists  and  Chemists  Handbook:  2d  ed,   1918,  p.  112. 


TABLE  XXVI. 

FACTORS  FOR  USE  IN  CALCULATING  RESULTS  OF  OIL 
SHALE  ASSAYS.1 


Weight  rf 
retort  charge 

Weight  of 
retort  charge 

(J  rams' 

Ounces 

Factor 

Grams 

Ounces 

Factor 

1 

2 

3 

1 

2 

3 

10 

.35 

.042 

310 

10.94 

1.294 

20 

.71 

.083 

320 

11.30 

1.335 

30 

1.06 

.125 

330 

11.65 

1.377 

40 

1.41 

.167 

340 

12.00 

1.419 

50 

1.76 

.209 

350 

12.36 

1.460 

60 

2.12 

.250 

360 

12.71 

1.502 

70 

2.47 

.292 

370 

13.06 

1.544 

80 

2.82 

.334 

380 

13.41 

1.586 

90 

3.18 

.376 

390 

13.77 

1.627 

100 

3.53 

.417 

400 

14.12 

1.669 

110 

3.88 

.459 

410 

14.47 

1.711 

120 

4.24 

.501 

420 

14.83 

1.753 

130 

4.59 

.542                i 

430 

15.18 

1.794 

140 

4.94 

.584 

440 

15.53 

1.836 

150 

5.29 

.626 

450 

15.88 

1.878 

160 

5.65 

.668 

460 

16.24 

1.919 

170 

6.00 

.709 

470 

16.59 

1.961 

180 

6.35 

.751 

480 

16.94 

2.003 

190 

6.71 

.793 

490 

17.30 

2.045 

200 

7.06 

.835 

500 

17.65 

2.086 

210 

7.41 

.876 

510 

18.00 

2.128 

220 

7.77 

.918 

520 

18.36 

2.170 

230 

8.12 

.960 

530 

18.71 

2.212 

240 

8.47 

1.001 

540 

19.06 

2.254 

250 

8.82 

1.043 

550 

19.41 

2.295 

260 

9.18 

1.085 

560 

19.77 

2.337 

270 

9.53 

1.127 

570 

20.12 

2.379 

280 

9.88 

1.168 

580 

20.47 

2.420 

290 

10.24 

1.201 

590 

20.83 

2.462 

300 

10.59 

1.252 

600 

21.18 

2.504 

For  any  given  weight  of  shale  used  (column  1  or  2),  select  the  cor- 
responding factor  in  column  3;  divide  the  number  of  cubic  centimeters  of  oil 
collected  by  this  factor  to  convert  into  gallons  of  oil  per  ton  of  shale.  For 
shale  charges  whose  weights  in  grams  are  not  even  multiples  of  ten,  it  will 
be  necessary  to  interpolate  to  obtain  the  proper  factor. 

1  Prepared  by  L.  C.  Karrick,   assistant  oil-shale  technologist,   Bureau  of 
Mines. 


68  SHORT  PAPERS  FROM  THE 

TABLE  XXVII. 

OTHER  FACTORS  FREQUENTLY  USED  IN  MAKING   OIL- 
SHALE  ASSAY  CALCULATIONS. 

Imperial  gallons  per  long  ton  to  United  States  gallons  per 

short     ton  ....................................................................................  Multiply  by  1.0716 

Pounds  per  long  ton  to  pounds  per  short  ton  ............................  Multiply  by  0.893 

Per    cent    nitrogen    to    pounds    amonium    sulphate    per    short 

ton     ............................................  ..........................................................  Multiply  by  92.4 


2,000   pounds=;907,185   grams. 
1   Cubic  foot  =  28,377   cubic  centimeters. 

cubic  centimeters  of  gas  obtained 
Cubic  feet  of  gas  per  ton_-,32.037  X  -  gramB  of  8haie  retorted  ~ 

,     cubic  centimeters  of  oil  obtained 
Gallons  of  oil  per  ton  =  239.66X  -  grams  of  ^ale  retorted 


OVERDUE. 


Gaylamount 
Pamphlet 

Binder 

Gaylord  Bros..  Inc. 

Stockton,  Calif. 

T.  M.  Reg.  U.S.  Pat.  Off. 


YC  '18642 


THE  UNIVERSITY  OF  CALIFORNIA  LIBRARY 


